Network Traffic

Data transmitted across a network (ex: Web, DNS, Mail, File, etc.), that is either summarized (ex: Netflow) and/or captured as raw data in an analyzable format (ex: PCAP)

ID: DS0029

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Platforms: Android, IaaS, Linux, Windows, iOS, macOS

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Collection Layers: Cloud Control Plane, Host, Network

Contributors: Center for Threat-Informed Defense (CTID); ExtraHop

Version: 1.1

Created: 20 October 2021

Last Modified: 20 April 2023

Version Permalink

Live Version

Data Components

Network Traffic: Network Connection Creation

Initial construction of a network connection, such as capturing socket information with a source/destination IP and port(s) (ex: Windows EID 5156, Sysmon EID 3, or Zeek conn.log)

Network Traffic: Network Connection Creation

Initial construction of a network connection, such as capturing socket information with a source/destination IP and port(s) (ex: Windows EID 5156, Sysmon EID 3, or Zeek conn.log)

Domain	ID		Name	Detects
Mobile	T1638		Adversary-in-the-Middle	Mobile security products can potentially detect rogue Wi-Fi access points if the adversary is attempting to decrypt traffic using an untrusted SSL certificate.
Enterprise	T1020		Automated Exfiltration	Monitor for newly constructed network connections associated with processes performing collection activity, especially those involving abnormal/untrusted hosts.
		.001	Traffic Duplication	Monitor for newly constructed network connections that are sent or received by abnormal or untrusted hosts.
Enterprise	T1197		BITS Jobs	Monitor for newly constructed network activity generated by BITS. BITS jobs use HTTP(S) and SMB for remote connections and are tethered to the creating user and will only function when that user is logged on (this rule applies even if a user attaches the job to a service account).
Enterprise	T1176		Browser Extensions	Monitor for newly constructed network connections that are sent or received by untrusted hosts.
Enterprise	T1612		Build Image on Host	Monitor for established network communications with anomalous IPs that have never been seen before in the environment that may indicate the download of malicious code.
Enterprise	T1602		Data from Configuration Repository	Monitor for newly constructed network connections that are sent or received by untrusted hosts or uncommon data flows. Consider analyzing packet contents to detect application layer protocols, leveraging SSL/TLS inspection for encrypted traffic, that do not follow the expected protocol standards and traffic flows (e.g. unauthorized, gratuitous, or anomalous traffic patterns attempting to access configuration content)
		.001	SNMP (MIB Dump)	Monitor for newly constructed network connections that are sent or received by untrusted hosts or uncommon data flows. Consider analyzing packet contents to detect application layer protocols, leveraging SSL/TLS inspection for encrypted traffic, that do not follow the expected protocol standards and traffic flows(e.g. snmp traffic originating from unauthorized or untrusted hosts, signature detection for strings mapped to device configuration(s), and anomolies in snmp request(s))
		.002	Network Device Configuration Dump	Monitor for newly constructed network connections that are sent or received by untrusted hosts or uncommon data flows. Consider analyzing packet contents to detect application layer protocols, leveraging SSL/TLS inspection for encrypted traffic, that do not follow the expected protocol standards and traffic flows (e.g. unauthorized, gratuitous, or anomalous traffic patterns attempting to access network configuration content)
Enterprise	T1039		Data from Network Shared Drive	Monitor for newly constructed network connections that may search network shares on computers they have compromised to find files of interest. Network Analysis frameworks such as Zeek can be used to capture, decode, and alert on network protocols such as SMB that revolve around network shares.
Enterprise	T1030		Data Transfer Size Limits	Monitor for newly constructed network connections that are sent or received by untrusted hosts or uncommon data flows (e.g. unusual network communications or suspicious communications sending fixed size data packets at regular intervals as well as unusually long connection patterns). Consider analyzing packet contents to detect application layer protocols, leveraging SSL/TLS inspection for encrypted traffic, that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, protocol port mismatch, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments (e.g. monitor anomalies in use of files that do not normally initiate network connections or unusual connections initiated
Enterprise	T1189		Drive-by Compromise	Monitor for newly constructed network connections to untrusted hosts that are used to send or receive data.
ICS	T0817		Drive-by Compromise	Monitor for newly constructed network connections to untrusted hosts that are used to send or receive data.
Enterprise	T1568		Dynamic Resolution	Monitor for newly constructed network connections that are sent or received by untrusted hosts.
		.001	Fast Flux DNS	Monitor for newly constructed network connections that may use Fast Flux DNS to hide a command and control channel behind an array of rapidly changing IP addresses linked to a single domain resolution.
Enterprise	T1114		Email Collection	Monitor for newly constructed network connections that are sent or received by untrusted hosts.
		.002	Remote Email Collection	Monitor for newly constructed network connections that are sent or received by untrusted hosts.
Enterprise	T1048		Exfiltration Over Alternative Protocol	Monitor for newly constructed network connections that are sent or received by untrusted hosts.
		.001	Exfiltration Over Symmetric Encrypted Non-C2 Protocol	Monitor for newly constructed network connections that are sent or received by untrusted hosts.
		.002	Exfiltration Over Asymmetric Encrypted Non-C2 Protocol	Monitor for newly constructed network connections that are sent or received by untrusted hosts.
		.003	Exfiltration Over Unencrypted Non-C2 Protocol	Monitor for newly constructed network connections that are sent or received by untrusted hosts.
Enterprise	T1041		Exfiltration Over C2 Channel	Monitor for newly constructed network connections that are sent or received by untrusted hosts. Note: Network Analysis frameworks such as Zeek can be used to capture, decode, and alert on TCP network connection creation.
Enterprise	T1011		Exfiltration Over Other Network Medium	Monitor for newly constructed network connections that may attempt to exfiltrate data over a different network medium than the command and control channel. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious. Note: Network Analysis frameworks such as Zeek can be used to capture, decode, and alert on TCP network connection creation. The below analytic is using an event ID from OSQuery.
		.001	Exfiltration Over Bluetooth	Monitor for newly constructed network connections that may attempt to exfiltrate data over Bluetooth rather than the command and control channel. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.
Enterprise	T1567		Exfiltration Over Web Service	Monitor for newly constructed network connections to web and cloud services associated with abnormal or non-browser processes.
		.002	Exfiltration to Cloud Storage	Monitor for newly constructed network connections to cloud services associated with abnormal or non-browser processes.
Enterprise	T1133		External Remote Services	Monitor for newly constructed network connections that may use Valid Accounts to access and/or persist within a network using External Remote Services. Use of External Remote Services may be legitimate depending on the environment and how it’s used. Other factors, such as access patterns and activity that occurs after a remote login, may indicate suspicious or malicious behavior using External Remote Services.
Enterprise	T1008		Fallback Channels	Monitor for newly constructed network connections that may use fallback or alternate communication channels if the primary channel is compromised or inaccessible in order to maintain reliable command and control and to avoid data transfer thresholds. Processes utilizing the network that do not normally have network communication or have never been seen before may be suspicious. Note: Network Analysis frameworks such as Zeek can be used to capture, decode, and alert on TCP network connection creation. The below analytic is using an event ID from OSQuery.
Enterprise	T1105		Ingress Tool Transfer	Monitor for newly constructed network connections that are sent or received by untrusted hosts or creating files on-system may be suspicious. Use of utilities, such as FTP, that does not normally occur may also be suspicious.
Enterprise	T1104		Multi-Stage Channels	Monitor for newly constructed network connections that are sent or received by untrusted hosts.
Enterprise	T1542		Pre-OS Boot	Monitor for newly constructed network device configuration and system image against a known-good version to discover unauthorized changes to system boot, startup configuration, or the running OS. The same process can be accomplished through a comparison of the run-time memory, though this is non-trivial and may require assistance from the vendor.
		.005	TFTP Boot	Monitor for newly constructed network device configuration and system image against a known-good version to discover unauthorized changes to system boot, startup configuration, or the running OS. ^[1] ^[2] The same process can be accomplished through a comparison of the run-time memory, though this is non-trivial and may require assistance from the vendor.
Enterprise	T1572		Protocol Tunneling	Monitor for newly constructed network connections that are sent or received by untrusted hosts.
Enterprise	T1090		Proxy	Monitor for newly constructed network connections that are sent or received by untrusted hosts.
		.001	Internal Proxy	Monitor for newly constructed network connections that are sent or received by untrusted hosts.
		.002	External Proxy	Monitor for newly constructed network connections that are sent or received by untrusted hosts.
		.003	Multi-hop Proxy	Monitor for newly constructed network connections that are sent or received by untrusted hosts.
Enterprise	T1219		Remote Access Software	Monitor for newly constructed network connections that are sent or received by untrusted hosts.
Enterprise	T1021		Remote Services	Monitor for newly constructed network connections that may use Valid Accounts to log into a service specifically designed to accept remote connections, such as RDP, telnet, SSH, and VNC. Monitor network connections involving common remote management protocols, such as ports tcp:3283 and tcp:5900, as well as ports tcp: 3389 and tcp:22 for remote login.
		.001	Remote Desktop Protocol	Monitor for newly constructed network connections (typically over port 3389) that may use Valid Accounts to log into a computer using the Remote Desktop Protocol (RDP). The adversary may then perform actions as the logged-on user. Other factors, such as access patterns and activity that occurs after a remote login, may indicate suspicious or malicious behavior with RDP.
		.002	SMB/Windows Admin Shares	Monitor for newly constructed network connections (typically over ports 139 or 445), especially those that are sent or received by abnormal or untrusted hosts. Correlate these network connections with remote login events and associated SMB-related activity such as file transfers and remote process execution. Note: Event ID is for Zeek but can also be implemented in other Network Analysis Frameworks by parsing & decoding captured SMB2 network traffic. Preference would be to detect smb2_write_response event (instead of smb2_write_request), because it would confirm the file was actually written to the remote destination. Unfortunately, Bro/Zeek does not have an event for that SMB message-type yet. From a network traffic capture standpoint, it’s important to capture the right traffic for this type of detection to function (e.g., all endpoint to endpoint if possible or workstation to server and workstation to workstation). As such, it is helpful to have a centralized server area where it is possible to monitor communications between servers and endpoints. Analytic 1 and 2 are very similar, with the key difference being that Implementation 2 is intended to capture multiple attempts at lateral movement originating from the same host within a short time period (5 minutes). smb2_write_request, smb1_write_andx_response is indication of an SMB file write to a Windows Admin File Share: ADMIN$ or C$ smb2_tree_connect_request, smb1_tree_connect_andx_request is observed originating from the same host, regardless of write-attempts and regardless of whether or not any connection is successful —just connection attempts— within a specified period of time (REPEATS 5 TIMES WITHIN 5 MINUTES FROM SAME src_ip). From a network traffic capture standpoint, it’s important to capture the right traffic for this type of detection to function (e.g., all endpoint to endpoint if possible or workstation to server and workstation to workstation). As such, it is helpful to have a centralized server area where it is possible to monitor communications between servers and endpoints.The Service Control Manager (SCM) can be used to copy a file to the ADMIN$ share and execute it as a service. This can be detected by looking for incoming RPC network connections to the Service Control Manager, followed by services.exe spawning a child process. Analytic 1 - Basic`source="*Zeek:SMB_Files" EventCode IN ("smb2_write_request", "smb1_write_andx_response", "smb2_tree_connect_request", "smb1_tree_connect_andx_request") AND (Path="ADMIN$" OR Path="C$")`
		.003	Distributed Component Object Model	Monitor for newly constructed network connections that may use Valid Accounts to interact with remote machines using Distributed Component Object Model (DCOM). The adversary may then perform actions as the logged-on user. Monitor for any influxes or abnormal increases in DCOM related Distributed Computing Environment/Remote Procedure Call (DCE/RPC) traffic (typically over port 135). Note: Network Analysis frameworks such as Zeek can be used to capture, decode, and alert on RPC network flows. Traffic to the RPC Endpoint Mapper will always have the destination port of 135. Assuming success, RPC traffic will continue to the endpoint. The endpoint and the client both bind to dynamically assigned ports (on Windows, this is typically greater than 49152). The traffic between the client and endpoint can be detected by looking at traffic to 135 followed by traffic where the source and destination ports are at least 49152.
		.004	SSH	Monitor for newly constructed network connections (typically port 22) that may use Valid Accounts to log into remote machines using Secure Shell (SSH). Use of SSH may be legitimate depending on the environment and how it’s used. Other factors, such as access patterns and activity that occurs after a remote login, may indicate suspicious or malicious behavior with SSH. Network Analysis Frameworks such as Zeek can be used to capture, decode, and alert on network traffic. Accordingly, they can be used to look for the creation of SSH network connections.
		.005	VNC	Monitor for newly constructed network connections that may use Valid Accounts to remotely control machines using Virtual Network Computing (VNC). Use of VNC may be legitimate depending on the environment and how it’s used. Other factors, such as access patterns and activity that occurs after a remote login, may indicate suspicious or malicious behavior using VNC.
		.006	Windows Remote Management	Monitor for newly constructed network connections using Windows Remote Management (WinRM), such as remote WMI connection attempts (typically over port 5985 when using HTTP and 5986 for HTTPS).
ICS	T0886		Remote Services	Monitor for newly constructed network connections into a service specifically designed to accept remote connections, such as RDP, Telnet, SSH, and VNC. Monitor network connections involving common remote management protocols, such as ports tcp:3283 and tcp:5900, as well as ports tcp:3389 and tcp:22 for remote logins. The adversary may use Valid Accounts to enable remote logins.
Enterprise	T1018		Remote System Discovery	Monitor for newly constructed network connections associated with pings/scans that may attempt to get a listing of other systems by IP address, hostname, or other logical identifier on a network that may be used for Lateral Movement from the current system.
Enterprise	T1496		Resource Hijacking	Monitor for newly constructed network connections that are sent or received by untrusted hosts, look for connections to/from strange ports, as well as reputation of IPs and URLs related cryptocurrency hosts.
Enterprise	T1029		Scheduled Transfer	Monitor for newly constructed network connections that are sent or received by untrusted hosts.
Enterprise	T1218		System Binary Proxy Execution	Monitor for newly constructed network connections that are sent or received by untrusted hosts.
		.003	CMSTP	Monitor for newly constructed network connections that are sent or received by untrusted hosts, such as Sysmon Event 3 (Network connection) where Image contains CMSTP.exe and DestinationIP is external. Note: Event IDs are for Sysmon (Event ID 1 - process create) and Windows Security Log (Event ID 4688 - a new process has been created). The Analytic looks for the creation of a new CMSTP.exe process which initiates a network connection to a non-local IP address. This is a specific implementation where CMSTP.exe can be leveraged to setup listeners that will receive and install malware from remote sources in a trusted fashion. Analytic 1 - CMSTP `(source="*WinEventLog:Microsoft-Windows-Sysmon/Operational" EventCode="3") Image="C:\Windows\System32\CMSTP.exe" \| WHERE ((!cidrmatch("10.0.0.0/8", SourceIp) AND !cidrmatch("192.168.0.0/16", SourceIp) AND !cidrmatch("172.16.0.0/12", SourceIp))`
		.005	Mshta	Monitor for newly constructed network connections that are sent or received by untrusted hosts.
		.007	Msiexec	Monitor for newly constructed network connections that are sent or received by untrusted hosts.
		.010	Regsvr32	Monitor for newly constructed network connections that are sent or received by untrusted hosts.
Enterprise	T1221		Template Injection	Monitor for newly constructed network connections that are sent or received by untrusted hosts.
Enterprise	T1205		Traffic Signaling	Monitor for newly constructed network connections that are sent or received by untrusted hosts.
		.001	Port Knocking	Monitor for newly constructed network connections that are sent or received by untrusted hosts.
		.002	Socket Filters	Monitor recently started applications creating raw socket connections.^[3]
Enterprise	T1204		User Execution	Monitor for newly constructed web-based network connections that are sent to malicious or suspicious destinations (e.g. destinations attributed to phishing campaigns). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments (e.g. monitor anomalies in use of files that do not normally initiate network connections or unusual connections initiated by regsvr32.exe, rundll.exe, .SCF, HTA, MSI, DLLs, or msiexec.exe).
		.001	Malicious Link	Monitor for newly constructed web-based network connections that are sent to malicious or suspicious destinations (e.g. destinations attributed to phishing campaigns). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments (e.g. monitor anomalies in use of files that do not normally initiate network connections or unusual connections initiated by regsvr32.exe, rundll.exe, .SCF, HTA, MSI, DLLs, or msiexec.exe).
ICS	T0863		User Execution	Monitor for newly constructed web-based network connections that are sent to malicious or suspicious destinations (e.g., destinations attributed to phishing campaigns). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments (e.g., monitor anomalies in use of files that do not normally initiate network connections or unusual connections initiated by regsvr32.exe, rundll.exe, SCF, HTA, MSI, DLLs, or msiexec.exe).
Enterprise	T1102		Web Service	Monitor for newly constructed network connections that are sent or received by untrusted hosts.
		.002	Bidirectional Communication	Monitor for newly constructed network connections that are sent or received by untrusted hosts.
		.003	One-Way Communication	Monitor for newly constructed network connections that are sent or received by untrusted hosts.
Mobile	T1481		Web Service	Many properly configured firewalls may naturally block command and control traffic.
		.001	Dead Drop Resolver	Many properly configured firewalls may naturally block command and control traffic.
		.002	Bidirectional Communication	Many properly configured firewalls may naturally block bidirectional command and control traffic.
		.003	One-Way Communication	Many properly configured firewalls may naturally block one-way command and control traffic.
Enterprise	T1047		Windows Management Instrumentation	Monitor network traffic for WMI connections for potential use to remotely edit configuration, start services, or query files. When remote WMI requests are over RPC it connects to a DCOM interface within the RPC group `netsvcs`. To detect this activity, a sensor is needed at the network level that can decode RPC traffic or on the host where the communication can be detected more natively, such as Event Tracing for Windows. Using wireshark/tshark decoders, the WMI interfaces can be extracted so that WMI activity over RPC can be detected. Although the description details how to detect remote WMI precisely, a decent estimate has been to look for the string RPCSS within the initial RPC connection on 135/tcp. It returns a superset of this activity, and will trigger on all DCOM-related services running within RPC, which is likely to also be activity that should be detected between hosts. More about RPCSS at : rpcss_dcom_interfaces.html Look for instances of the WMI querying in network traffic, and find the cases where a process is launched immediately after a connection is seen. This essentially merges the request to start a remote process via WMI with the process execution. If other processes are spawned from wmiprvse.exe in this time frame, it is possible for race conditions to occur, and the wrong process may be merged. If this is the case, it may be useful to look deeper into the network traffic to see if the desired command can be extracted. After the WMI connection has been initialized, a process can be remotely launched using the command: `wmic /node:"" process call create ""`, which is detected in the third Detection Pseudocode. This leaves artifacts at both a network (RPC) and process (command line) level. When `wmic.exe` (or the schtasks API) is used to remotely create processes, Windows uses RPC (135/tcp) to communicate with the the remote machine. After RPC authenticates, the RPC endpoint mapper opens a high port connection, through which the schtasks Remote Procedure Call is actually implemented. With the right packet decoders, or by looking for certain byte streams in raw data, these functions can be identified. When the command line is executed, it has the parent process of `C:\windows\system32\wbem\WmiPrvSE.exe`. This analytic looks for these two events happening in sequence, so that the network connection and target process are output. Certain strings can be identifiers of the WMI by looking up the interface UUID for `IRemUnknown2` in different formats- UUID `00000143-0000-0000-c000-000000000046` (decoded)- Hex `43 01 00 00 00 00 00 00 c0 00 00 00 00 00 00 46` (raw)- ASCII `CF` (printable text only) This identifier is present three times during the RPC request phase. Any sensor that has access to the byte code as raw, decoded, or ASCII could implement this analytic. The transfer syntax is- UUID `8a885d04-1ceb-11c9-9fe8-08002b104860` (decoded)- Hex `04 5d 88 8a eb 1c c9 11 9f e8 08 00 2b 10 48 60` (raw)- ASCII `]+H`` (printable text only) Thus, a great ASCII based signature is- `CF]+HCFCFhost"` Note: To detect WMI over RPC (using DCOM), a sensor needs to exist that has the insight into individual connections and can actually decode and make sense of RPC traffic. Specifically, WMI can be detected by looking at RPC traffic where the target interface matches that of WMI, which is IRemUnknown2. Look for instances of the WMI querying in network traffic, and find the cases where a process is launched immediately after a connection is seen. This essentially merges the request to start a remote process via WMI with the process execution. If other processes are spawned from wmiprvse.exe in this time frame, it is possible for race conditions to occur, and the wrong process may be merged. If this is the case, it may be useful to look deeper into the network traffic to see if the desired command can be extracted. Analytic 1 - Remote WMI over RPC `source="*Zeek:RPC" dest_port="135" protocol_rpc_interface="IRemUnknown2"`

Network Traffic: Network Traffic Content

Logged network traffic data showing both protocol header and body values (ex: PCAP)

Network Traffic: Network Traffic Content

Logged network traffic data showing both protocol header and body values (ex: PCAP)

Domain	ID		Name	Detects
Enterprise	T1087	.002	Account Discovery: Domain Account	Monitor and analyze traffic patterns and packet inspection associated to LDAP and MSRPC that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure).
ICS	T0800		Activate Firmware Update Mode	Monitor ICS automation network protocols for information that an asset has been placed into Firmware Update Mode.
Enterprise	T1595		Active Scanning	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
		.002	Vulnerability Scanning	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
		.003	Wordlist Scanning	Monitor for suspicious network traffic that could be indicative of scanning, such as large quantities originating from a single source (especially if the source is known to be associated with an adversary/botnet).
Enterprise	T1557		Adversary-in-the-Middle	Monitor network traffic for anomalies associated with known AiTM behavior.
		.001	LLMNR/NBT-NS Poisoning and SMB Relay	Monitor for traffic on ports UDP 5355 and UDP 137 if LLMNR/NetBIOS is disabled by security policy.
		.002	ARP Cache Poisoning	Monitor network traffic for unusual ARP traffic, gratuitous ARP replies may be suspicious. Consider collecting changes to ARP caches across endpoints for signs of ARP poisoning. For example, if multiple IP addresses map to a single MAC address, this could be an indicator that the ARP cache has been poisoned.
		.003	DHCP Spoofing	Monitor network traffic for suspicious/malicious behavior involving DHCP, such as changes in DNS and/or gateway parameters. Additionally, monitor network traffic for rogue DHCPv6 activity.
ICS	T0830		Adversary-in-the-Middle	Monitor network traffic for anomalies associated with known AiTM behavior. For Collection activity where transmitted data is not manipulated, anomalies may be present in network management protocols (e.g., ARP, DHCP).
Enterprise	T1071		Application Layer Protocol	Monitor and analyze traffic patterns and packet inspection associated to protocol(s), leveraging SSL/TLS inspection for encrypted traffic, that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
		.001	Web Protocols	Monitor and analyze traffic patterns and packet inspection associated to protocol(s), leveraging SSL/TLS inspection for encrypted traffic, that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
		.002	File Transfer Protocols	Monitor and analyze traffic patterns and packet inspection associated to protocol(s), leveraging SSL/TLS inspection for encrypted traffic, that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
		.003	Mail Protocols	Monitor and analyze traffic patterns and packet inspection associated to protocol(s), leveraging SSL/TLS inspection for encrypted traffic, that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
		.004	DNS	Monitor and analyze traffic patterns and packet inspection associated to protocol(s), leveraging SSL/TLS inspection for DNS over TLS (DoT) and DNS over HTTPS (DoH), that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
ICS	T0802		Automated Collection	Monitor for information collection on assets that may indicate deviations from standard operational tools. Examples include unexpected industrial automation protocol functions, new high volume communication sessions, or broad collection across many hosts within the network.
Enterprise	T1020		Automated Exfiltration	Monitor network traffic content for evidence of data exfiltration, such as gratuitous or anomalous outbound traffic containing collected data. Consider correlation with process monitoring and command lines associated with collection and exfiltration.
ICS	T0806		Brute Force I/O	Monitor network traffic for ICS functions related to write commands for an excessive number of I/O points or manipulating a single value an excessive number of times.
Enterprise	T1612		Build Image on Host	Monitor for network traffic associated with requests and/or downloads of container images, especially those that may be anomalous or known malicious.
ICS	T0892		Change Credential	Monitor for device credential changes observable in automation or management network protocols.
ICS	T0858		Change Operating Mode	Monitor ICS management protocols for functions that change an asset’s operating mode.
ICS	T0885		Commonly Used Port	Monitor for mismatches between protocols and their expected ports (e.g., non-HTTP traffic on tcp:80). Analyze packet contents to detect communications that do not follow the expected protocol behavior for the port that is being used.^[4]
Enterprise	T1586		Compromise Accounts	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
		.001	Social Media Accounts	Monitor and analyze traffic patterns and packet inspection associated to protocol(s), leveraging SSL/TLS inspection for encrypted traffic, that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
ICS	T0884		Connection Proxy	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g., extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g., monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
Enterprise	T1659		Content Injection	Monitor for other unusual network traffic that may indicate additional malicious content transferred to the system. Use network intrusion detection systems, sometimes with SSL/TLS inspection, to look for known malicious payloads, content obfuscation, and exploit code.
Enterprise	T1132		Data Encoding	Monitor for network data for uncommon data flows (e.g., a client sending significantly more data than it receives from a server). Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious. Analyze packet contents to detect communications that do not follow the expected protocol behavior for the port that is being used. Note: Network Analysis frameworks such as Zeek can be used to capture, decode, and alert on network protocols and packet contents.
		.001	Standard Encoding	Monitor for network data for uncommon data flows (e.g., a client sending significantly more data than it receives from a server). Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious. Analyze packet contents to detect communications that do not follow the expected protocol behavior for the port that is being used.
		.002	Non-Standard Encoding	Monitor for network data for uncommon data flows (e.g., a client sending significantly more data than it receives from a server). Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious. Analyze packet contents to detect communications that do not follow the expected protocol behavior for the port that is being used.
Enterprise	T1602		Data from Configuration Repository	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g. unauthorized, gratuitous, or anomalous traffic patterns attempting to access configuration content)
		.001	SNMP (MIB Dump)	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flow (e.g. snmp traffic originating from unauthorized or untrusted hosts, signature detection for strings mapped to device configuration(s), and anomolies in snmp request(s))
		.002	Network Device Configuration Dump	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g. unauthorized, gratuitous, or anomalous traffic patterns attempting to access network configuration content)
Enterprise	T1039		Data from Network Shared Drive	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
Enterprise	T1565		Data Manipulation	Monitor for networks that solicits and obtains the configuration information of the queried device.
		.002	Transmitted Data Manipulation	Monitor for networks that solicits and obtains the configuration information of the queried device.
Enterprise	T1001		Data Obfuscation	Monitor and analyze traffic patterns and packet inspection associated to protocol(s), leveraging SSL/TLS inspection for encrypted traffic, that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
		.001	Junk Data	Monitor and analyze traffic patterns and packet inspection associated to protocol(s), leveraging SSL/TLS inspection for encrypted traffic, that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
		.002	Steganography	Monitor and analyze traffic patterns and packet inspection associated to protocol(s), leveraging SSL/TLS inspection for encrypted traffic, that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure).
		.003	Protocol Impersonation	Monitor and analyze traffic patterns and packet inspection associated to protocol(s), leveraging SSL/TLS inspection for encrypted traffic, that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
Enterprise	T1491		Defacement	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g. unauthorized, gratuitous, or anomalous traffic patterns attempting to access internal and external websites and services). Consider correlating with application monitoring for indication of unplanned service interruptions or unauthorized content changes.
		.001	Internal Defacement	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
		.002	External Defacement	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
ICS	T0812		Default Credentials	Monitor network traffic for default credential use in protocols that allow unencrypted authentication.
ICS	T0814		Denial of Service	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g., extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g., monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
ICS	T0868		Detect Operating Mode	Monitor ICS automation network protocols for functions related to reading an asset’s operating mode. In some cases, there may be multiple ways to detect a device’s operating mode, one of which is typically used in the operational environment. Monitor for the operating mode being checked in unexpected ways.
ICS	T0816		Device Restart/Shutdown	Monitor ICS automation protocols for functions that restart or shutdown a device. Commands to restart or shutdown devices may also be observable in traditional IT management protocols.
Enterprise	T1482		Domain Trust Discovery	Monitor and analyze traffic patterns and packet inspection associated to LDAP and MSRPC that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure).
Mobile	T1407		Download New Code at Runtime	Mobile security products may provide URL inspection services that could determine if a domain being visited is malicious.
Enterprise	T1189		Drive-by Compromise	Monitor for other unusual network traffic that may indicate additional tools transferred to the system. Use network intrusion detection systems, sometimes with SSL/TLS inspection, to look for known malicious scripts (recon, heap spray, and browser identification scripts have been frequently reused), common script obfuscation, and exploit code.
ICS	T0817		Drive-by Compromise	Monitor for unusual network traffic that may indicate additional tools transferred to the system. Use network intrusion detection systems, sometimes with SSL/TLS inspection, to look for known malicious scripts (recon, heap spray, and browser identification scripts have been frequently reused), common script obfuscation, and exploit code.
Enterprise	T1568		Dynamic Resolution	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
		.003	DNS Calculation	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
Enterprise	T1573		Encrypted Channel	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
		.001	Symmetric Cryptography	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
		.002	Asymmetric Cryptography	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
Enterprise	T1499		Endpoint Denial of Service	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
		.001	OS Exhaustion Flood	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
		.002	Service Exhaustion Flood	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
		.003	Application Exhaustion Flood	Monitor and analyze traffic patterns and packet inspection associated to protocol(s), leveraging SSL/TLS inspection for encrypted traffic, that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
		.004	Application or System Exploitation	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
Enterprise	T1585		Establish Accounts	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
		.001	Social Media Accounts	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
Enterprise	T1048		Exfiltration Over Alternative Protocol	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
		.001	Exfiltration Over Symmetric Encrypted Non-C2 Protocol	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
		.002	Exfiltration Over Asymmetric Encrypted Non-C2 Protocol	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
		.003	Exfiltration Over Unencrypted Non-C2 Protocol	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
Enterprise	T1041		Exfiltration Over C2 Channel	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
Enterprise	T1011		Exfiltration Over Other Network Medium	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
		.001	Exfiltration Over Bluetooth	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
Enterprise	T1567		Exfiltration Over Web Service	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
		.001	Exfiltration to Code Repository	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
		.002	Exfiltration to Cloud Storage	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
		.003	Exfiltration to Text Storage Sites	Monitor and analyze network traffic for exfiltration attempts using text storage sites, i.e. POST requests to text storage sites.
		.004	Exfiltration Over Webhook	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g., extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g., monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
Enterprise	T1190		Exploit Public-Facing Application	Use deep packet inspection to look for artifacts of common exploit traffic, such as SQL injection strings or known payloads. For example, monitor for successively chained functions that adversaries commonly abuse (i.e. gadget chaining) through unsafe deserialization to exploit publicly facing applications for initial access.^[5]
ICS	T0819		Exploit Public-Facing Application	Use deep packet inspection to look for artifacts of common exploit traffic, such as known payloads.
Enterprise	T1210		Exploitation of Remote Services	Use deep packet inspection to look for artifacts of common exploit traffic, such as known payloads.
Mobile	T1428		Exploitation of Remote Services	Network traffic analysis could reveal patterns of compromise if devices attempt to access unusual targets or resources.
ICS	T0866		Exploitation of Remote Services	Use deep packet inspection to look for artifacts of common exploit traffic, such as known payloads.
Enterprise	T1133		External Remote Services	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
Enterprise	T1187		Forced Authentication	For internal traffic, monitor the workstation-to-workstation unusual (vs. baseline) SMB traffic. For many networks there should not be any, but it depends on how systems on the network are configured and where resources are located.
Enterprise	T1589		Gather Victim Identity Information	Monitor for suspicious network traffic that could be indicative of probing for user information, such as large/iterative quantities of authentication requests originating from a single source (especially if the source is known to be associated with an adversary/botnet). Analyzing web metadata may also reveal artifacts that can be attributed to potentially malicious activity, such as referer or user-agent string HTTP/S fields.
		.002	Email Addresses	Monitor for suspicious network traffic that could be indicative of probing for email addresses and/or usernames, such as large/iterative quantities of authentication requests originating from a single source (especially if the source is known to be associated with an adversary/botnet). Analyzing web metadata may also reveal artifacts that can be attributed to potentially malicious activity, such as referer or user-agent string HTTP/S fields.
Enterprise	T1615		Group Policy Discovery	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
ICS	T0891		Hardcoded Credentials	Monitor network traffic for hardcoded credential use in protocols that allow unencrypted authentication.
Enterprise	T1665		Hide Infrastructure	Network detection systems may be able to identify traffic for specific adversary command and control infrastructure. Correlate network traffic with data and patterns from Internet-facing resources gathered from scans to gain further insight into potential adversary C2 networks.
Enterprise	T1070		Indicator Removal	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
		.005	Network Share Connection Removal	Monitoring for SMB traffic between systems may also be captured and decoded to look for related network share session and file transfer activity.
Enterprise	T1105		Ingress Tool Transfer	Monitor network traffic content for files and other potentially malicious content, especially data coming in from abnormal/unknown domain and IPs.
Enterprise	T1534		Internal Spearphishing	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
ICS	T0883		Internet Accessible Device	Monitor for unusual logins to Internet connected devices or unexpected protocols to/from the Internet. Network traffic content will provide valuable context and details about the content of network flows.
Enterprise	T1570		Lateral Tool Transfer	Monitor for unusual processes with internal network connections creating files on-system may be suspicious Note: Analytic Event Type is for Zeek but can also be implemented in other Network Analysis Frameworks by parsing & decoding captured SMB2 network traffic. From a network traffic capture standpoint, it’s important to capture the right traffic for this type of detection to function (e.g., all endpoint to endpoint if possible or workstation to server and workstation to workstation). As such, it is helpful to have a centralized server area where it is possible to monitor communications between servers and endpoints.
ICS	T0867		Lateral Tool Transfer	Monitor for unusual processes with internal network connections creating files on-system which may be suspicious.
ICS	T0838		Modify Alarm Settings	Monitor for alarm setting changes observable in automation or management network protocols.
ICS	T0836		Modify Parameter	Monitor ICS management protocols for parameter changes, including for unexpected values, changes far exceeding standard values, or for parameters being changed in an unexpected way (e.g., via a new function, at an unusual time).
ICS	T0889		Modify Program	Monitor device management protocols for functions that modify programs such as online edit and program append events.
ICS	T0839		Module Firmware	Monitor ICS management protocols / file transfer protocols for protocol functions related to firmware changes.
ICS	T0801		Monitor Process State	Monitor ICS automation network protocols for functions related to reading an operational process state (e.g., "Read" function codes in protocols like DNP3 or Modbus). In some cases, there may be multiple ways to monitor an operational process’ state, one of which is typically used in the operational environment. Monitor for the operating mode being checked in unexpected ways.
Enterprise	T1599		Network Boundary Bridging	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
		.001	Network Address Translation Traversal	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
Enterprise	T1095		Non-Application Layer Protocol	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
Enterprise	T1571		Non-Standard Port	Analyze packet contents to detect communications that do not follow the expected protocol behavior for the port that is being used.
Enterprise	T1003		OS Credential Dumping	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
		.006	DCSync	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
Enterprise	T1566		Phishing	Monitor and analyze SSL/TLS traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)). Filtering based on DKIM+SPF or header analysis can help detect when the email sender is spoofed.^[6]^[7]
		.001	Spearphishing Attachment	Monitor and analyze SSL/TLS traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)). Filtering based on DKIM+SPF or header analysis can help detect when the email sender is spoofed.^[6]^[7]
		.002	Spearphishing Link	Monitor and analyze SSL/TLS traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g. extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)). Furthermore, monitor network traffic for cloned sites as well as homographs via the use of internationalized domain names abusing different character sets (e.g. Cyrillic vs Latin versions of trusted sites).
		.003	Spearphishing via Service	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
Mobile	T1660		Phishing	Mobile security products may provide URL inspection services that could determine if a domain being visited is malicious.
Enterprise	T1598		Phishing for Information	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
		.001	Spearphishing Service	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
		.002	Spearphishing Attachment	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
		.003	Spearphishing Link	Monitor and analyze traffic patterns and packet inspection associated to protocol(s), leveraging SSL/TLS inspection for encrypted traffic, that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)). Furthermore, monitor network traffic for homographs via the use of internationalized domain names abusing different character sets (e.g. Cyrillic vs Latin versions of trusted sites). Also monitor and analyze traffic patterns and packet inspection for indicators of cloned websites. For example, if adversaries use HTTrack to clone websites, `Mirrored from (victim URL)` may be visible in the HTML section of packets.
ICS	T0861		Point & Tag Identification	Monitor ICS automation protocols for anomalies related to reading point or tag data, such as new assets using these functions, changes in volume or timing, or unusual information being queried. Many protocols provide multiple ways to achieve the same result (e.g., functions with/without an acknowledgment or functions that operate on a single point vs. multiple points). Monitor for changes in the functions used.
ICS	T0843		Program Download	Monitor for protocol functions related to program download or modification. Program downloads may be observable in ICS automation protocols and remote management protocols.
ICS	T0845		Program Upload	Program uploads may be observable in ICS management protocols or file transfer protocols. Note when protocol functions related to program uploads occur. In cases where the ICS protocols is not well understood, one option is to examine network traffic for the program files themselves using signature-based tools.
Enterprise	T1572		Protocol Tunneling	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
Enterprise	T1090		Proxy	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
		.001	Internal Proxy	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
		.002	External Proxy	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
		.003	Multi-hop Proxy	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
		.004	Domain Fronting	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
Enterprise	T1219		Remote Access Software	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
Enterprise	T1563		Remote Service Session Hijacking	Monitor and analyze traffic patterns and packet inspection associated to protocol(s), leveraging SSL/TLS inspection for encrypted traffic, that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
		.001	SSH Hijacking	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
		.002	RDP Hijacking	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)). Network Analysis frameworks such as Zeek can be used to capture, decode, and alert on network protocols including RDP.
ICS	T0846		Remote System Discovery	Monitor for anomalies related to discovery related ICS functions, including devices that have not previously used these functions or for functions being sent to many outstations. Note that some ICS protocols use broadcast or multicast functionality, which may produce false positives. Also monitor for hosts enumerating network connected resources using non-ICS enterprise protocols.
ICS	T0888		Remote System Information Discovery	Monitor for anomalies related to discovery related ICS functions, including devices that have not previously used these functions or for functions being sent to many outstations. Note that some ICS protocols use broadcast or multicast functionality, which may produce false positives. Also monitor for hosts enumerating network connected resources using non-ICS enterprise protocols.
Enterprise	T1496		Resource Hijacking	Monitor network traffic content for resources of co-opted systems to complete resource-intensive tasks, which may impact system and/or hosted service availability. Note: Destination Host Name is not a comprehensive list of potential cryptocurrency URLs. This analytic has a hardcoded domain name which may change.
Enterprise	T1207		Rogue Domain Controller	Monitor and analyze network traffic associated with data replication (such as calls to DrsAddEntry, DrsReplicaAdd, and especially GetNCChanges) between DCs as well as to/from non DC hosts. ^[8]^[9] DC replication will naturally take place every 15 minutes but can be triggered by an adversary or by legitimate urgent changes (ex: passwords).
ICS	T0848		Rogue Master	Monitor for unexpected ICS protocol functions from new and existing devices. Monitoring known devices requires ICS function level insight to determine if an unauthorized device is issuing commands (e.g., a historian).
Enterprise	T1505		Server Software Component	Monitor and analyze traffic patterns and packet inspection associated to protocol(s), leveraging SSL/TLS inspection for encrypted traffic, that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)). ^[10]
		.003	Web Shell	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
ICS	T0865		Spearphishing Attachment	Monitor network traffic for suspicious email attachments. Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g., monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)). Use web proxies to review content of emails including sender information, headers, and attachments for potentially malicious content.
ICS	T0856		Spoof Reporting Message	Spoofed reporting messages may be detected by reviewing the content of automation protocols, either through detecting based on expected values or comparing to other out of band process data sources. Spoofed messages may not precisely match legitimate messages which may lead to malformed traffic, although traffic may be malformed for many benign reasons. Monitor reporting messages for changes in how they are constructed. Various techniques enable spoofing a reporting message. Consider monitoring for Rogue Master and Adversary-in-the-Middle activity.
ICS	T0869		Standard Application Layer Protocol	Monitor and analyze traffic patterns and packet inspection associated to protocol(s), leveraging SSL/TLS inspection for encrypted traffic, that do not follow the expected protocol standards and traffic flows (e.g., extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g., monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
ICS	T0857		System Firmware	Monitor ICS management protocols / file transfer protocols for protocol functions related to firmware changes.
Enterprise	T1033		System Owner/User Discovery	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)). Note: Network Analysis frameworks such as Zeek can be used to capture, decode, and alert on network protocols.
Enterprise	T1221		Template Injection	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
Enterprise	T1205		Traffic Signaling	Monitor and analyze network packet contents to detect application layer protocols, leveraging SSL/TLS inspection for encrypted traffic, that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, protocol port mismatch, anomalous syntax, or structure). Consider packet inspection for Wake-on-LAN magic packet consists of 6 bytes of `FF` followed by sixteen repetitions of the target system's IEEE address. Seeing this string anywhere in a packet's payload may be indicative of a Wake-on-LAN attempt.^[11]
Enterprise	T1537		Transfer Data to Cloud Account	Monitor network traffic content for evidence of data exfiltration, such as gratuitous or anomalous internal traffic containing collected data. Consider correlation with process monitoring and command lines associated with collection and exfiltration.
Enterprise	T1199		Trusted Relationship	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure) from a trusted entity. Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
ICS	T0855		Unauthorized Command Message	Monitor for unexpected ICS protocol command functions to controllers from existing master devices (including from new processes) or from new devices. The latter is like detection for Rogue Master but requires ICS function level insight to determine if an unauthorized device is issuing commands (e.g., a historian). Monitoring for unexpected or problematic values below the function level will provide better insights into potentially malicious activity but at the cost of additional false positives depending on the underlying operational process.
Enterprise	T1204		User Execution	Monitor and analyze traffic patterns and packet inspection associated with web-based network connections that are sent to malicious or suspicious detinations (e.g. destinations attributed to phishing campaigns). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments (e.g. monitor anomalies in use of files that do not normally initiate network connections or unusual connections initiated by regsvr32.exe, rundll.exe, .SCF, HTA, MSI, DLLs, or msiexec.exe).
		.001	Malicious Link	Monitor and analyze traffic patterns and packet inspection associated with web-based network connections that are sent to malicious or suspicious detinations (e.g. destinations attributed to phishing campaigns). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments (e.g. monitor anomalies in use of files that do not normally initiate network connections or unusual connections initiated by regsvr32.exe, rundll.exe, .SCF, HTA, MSI, DLLs, or msiexec.exe).
ICS	T0863		User Execution	Monitor and analyze traffic patterns and packet inspection associated with web-based network connections that are sent to malicious or suspicious destinations (e.g., destinations attributed to phishing campaigns). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments (e.g., monitor anomalies in use of files that do not normally initiate network connections or unusual connections initiated by regsvr32.exe, rundll.exe, SCF, HTA, MSI, DLLs, or msiexec.exe).
Enterprise	T1102		Web Service	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
		.001	Dead Drop Resolver	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
		.002	Bidirectional Communication	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
		.003	One-Way Communication	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).

Network Traffic: Network Traffic Flow

Summarized network packet data, with metrics, such as protocol headers and volume (ex: Netflow or Zeek http.log)

Network Traffic: Network Traffic Flow

Summarized network packet data, with metrics, such as protocol headers and volume (ex: Netflow or Zeek http.log)

Domain	ID		Name	Detects
Enterprise	T1595		Active Scanning	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.
		.001	Scanning IP Blocks	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.
		.002	Vulnerability Scanning	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.
Enterprise	T1557		Adversary-in-the-Middle	Monitor for network traffic originating from unknown/unexpected hardware devices. Local network traffic metadata (such as source MAC addressing) as well as usage of network management protocols such as DHCP may be helpful in identifying hardware.
		.001	LLMNR/NBT-NS Poisoning and SMB Relay	Monitor for network traffic originating from unknown/unexpected hardware devices. Local network traffic metadata (such as source MAC addressing) as well as usage of network management protocols such as DHCP may be helpful in identifying hardware.
		.002	ARP Cache Poisoning	Monitor for network traffic originating from unknown/unexpected hardware devices. Local network traffic metadata (such as source MAC addressing) as well as usage of network management protocols such as DHCP may be helpful in identifying hardware.
		.003	DHCP Spoofing	Monitor network traffic for anomalies associated with known AiTM behavior. Consider monitoring for modifications to system configuration files involved in shaping network traffic flow.
ICS	T0830		Adversary-in-the-Middle	Monitor for network traffic originating from unknown/unexpected hosts. Local network traffic metadata (such as source MAC addressing) as well as usage of network management protocols such as DHCP may be helpful in identifying hardware. For added context on adversary procedures and background see Adversary-in-the-Middle and applicable sub-techniques.
ICS	T0878		Alarm Suppression	Monitor for loss of network traffic which could indicate alarms are being suppressed. A loss of expected communications associated with network protocols used to communicate alarm events or process data could indicate this technique is being used. This will not directly detect the technique’s execution, but instead may provide additional evidence that the technique has been used and may complement other detections.
Enterprise	T1071		Application Layer Protocol	Monitor and analyze traffic flows that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, or gratuitous or anomalous traffic patterns). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
		.001	Web Protocols	Monitor for web traffic to/from known-bad or suspicious domains and analyze traffic flows that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, or gratuitous or anomalous traffic patterns). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
		.002	File Transfer Protocols	Monitor and analyze traffic flows that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, or gratuitous or anomalous traffic patterns). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
		.003	Mail Protocols	Monitor and analyze traffic flows that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, or gratuitous or anomalous traffic patterns). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
		.004	DNS	Monitor for DNS traffic to/from known-bad or suspicious domains and analyze traffic flows that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, or gratuitous or anomalous traffic patterns). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
Enterprise	T1020		Automated Exfiltration	Monitor and analyze network flows associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, or gratuitous or anomalous traffic patterns). Consider analyzing newly constructed network connections that are sent or received by untrusted hosts, unexpected hardware devices, or other uncommon data flows.
		.001	Traffic Duplication	Monitor and analyze network flows associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, or gratuitous or anomalous traffic patterns). Consider analyzing newly constructed network connections that are sent or received by untrusted hosts, unexpcted hardware devices, or other uncommon data flows.
ICS	T0803		Block Command Message	Monitor for a loss of network communications, which may indicate this technique is being used.
ICS	T0804		Block Reporting Message	Monitor for a loss of network communications, which may indicate this technique is being used.
ICS	T0805		Block Serial COM	Monitor for a loss of network communications, which may indicate this technique is being used.
Enterprise	T1612		Build Image on Host	Monitor for established network communications with anomalous IPs that have never been seen before in the environment that may indicate the download of malicious code.
ICS	T0885		Commonly Used Port	Analyze network data for uncommon data flows (e.g., new protocols in use between hosts, unexpected ports in use). Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.
ICS	T0884		Connection Proxy	Monitor for known proxy protocols (e.g., SOCKS, Tor, peer-to-peer protocols) and tool usage (e.g., Squid, peer-to-peer software) on the network that are not part of normal operations. Also monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.
Enterprise	T1543	.003	Create or Modify System Process: Windows Service	Monitor for several ways that code can execute on a remote host. One of the most common methods is via the Windows Service Control Manager (SCM), which allows authorized users to remotely create and modify services. Several tools, such as PsExec, use this functionality. When a client remotely communicates with the Service Control Manager, there are two observable behaviors. First, the client connects to the RPC Endpoint Mapper over 135/tcp. This handles authentication, and tells the client what port the endpoint—in this case the SCM—is listening on. Then, the client connects directly to the listening port on services.exe. If the request is to start an existing service with a known command line, the the SCM process will run the corresponding command. This compound behavior can be detected by looking for services.exe receiving a network connection and immediately spawning a child process.
Enterprise	T1039		Data from Network Shared Drive	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious. Network Analysis frameworks such as Zeek can be used to capture, decode, and alert on network protocols such as SMB that revolve around network shares. Although there may be more native ways to detect detailed SMB events on the host, they can be extracted out of network traffic. With the right protocol decoders, port 445 traffic can be filtered and even the file path (relative to the share) can be retrieved. Looking at this activity more closely to obtain an adequate sense of situational awareness may make it possible to detect adversaries moving between hosts in a way that deviates from normal activity. Because SMB traffic is heavy in many environments, this analytic may be difficult to turn into something that can be used to quickly detect an APT. In some cases, it may make more sense to run this analytic in a forensic fashion. Looking through and filtering its output after an intrusion has been discovered may be helpful in identifying the scope of compromise.
Enterprise	T1565		Data Manipulation	Monitor for network traffic originating from unknown/unexpected hardware devices.
		.002	Transmitted Data Manipulation	Monitor for network traffic originating from unknown/unexpected hardware devices.
Enterprise	T1030		Data Transfer Size Limits	Monitor and analyze traffic flows that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, or gratuitous or anomalous traffic patterns). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
ICS	T0814		Denial of Service	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.
ICS	T0816		Device Restart/Shutdown	Monitor for a loss of network communications, which may indicate a device has been shutdown or restarted. This will not directly detect the technique’s execution, but instead may provide additional evidence that the technique has been used and may complement other detections.
Enterprise	T1568		Dynamic Resolution	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.
		.001	Fast Flux DNS	In general, detecting usage of fast flux DNS is difficult due to web traffic load balancing that services client requests quickly. In single flux cases only IP addresses change for static domain names. In double flux cases, nothing is static. Defenders such as domain registrars and service providers are likely in the best position for detection.
		.002	Domain Generation Algorithms	Detecting dynamically generated domains can be challenging due to the number of different DGA algorithms, constantly evolving malware families, and the increasing complexity of the algorithms. There is a myriad of approaches for detecting a pseudo-randomly generated domain name, including using frequency analysis, Markov chains, entropy, proportion of dictionary words, ratio of vowels to other characters, and more. ^[12] CDN domains may trigger these detections due to the format of their domain names. In addition to detecting a DGA domain based on the name, another more general approach for detecting a suspicious domain is to check for recently registered names or for rarely visited domains.Machine learning approaches to detecting DGA domains have been developed and have seen success in applications. One approach is to use N-Gram methods to determine a randomness score for strings used in the domain name. If the randomness score is high, and the domains are not whitelisted (CDN, etc), then it may be determined if a domain is related to a legitimate host or DGA. ^[13] Another approach is to use deep learning to classify domains as DGA-generated^[14]]
Enterprise	T1499		Endpoint Denial of Service	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.
		.001	OS Exhaustion Flood	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.
		.002	Service Exhaustion Flood	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.
		.003	Application Exhaustion Flood	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.
		.004	Application or System Exploitation	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.
Enterprise	T1048		Exfiltration Over Alternative Protocol	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.
		.001	Exfiltration Over Symmetric Encrypted Non-C2 Protocol	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.
		.002	Exfiltration Over Asymmetric Encrypted Non-C2 Protocol	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.
		.003	Exfiltration Over Unencrypted Non-C2 Protocol	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.
Enterprise	T1041		Exfiltration Over C2 Channel	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.
Enterprise	T1011		Exfiltration Over Other Network Medium	Monitor network data for uncommon data flows., such as the usage of abnormal/unexpected protocols.
		.001	Exfiltration Over Bluetooth	Monitor network data for uncommon data flows., such as the usage of abnormal/unexpected protocols.
Enterprise	T1567		Exfiltration Over Web Service	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.
		.001	Exfiltration to Code Repository	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious. Monitor for use of code repositories for data exfiltration.
		.002	Exfiltration to Cloud Storage	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious. Monitor for cloud storages for data exfiltration.
		.003	Exfiltration to Text Storage Sites	Monitor network data for uncommon data flows, specifically to text storage sites such as `Pastebin[.]com`, `Paste[.]ee`, and `Pastebin[.]pl`.
		.004	Exfiltration Over Webhook	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.
Enterprise	T1133		External Remote Services	Monitor for network traffic originating from unknown/unexpected hardware devices. Local network traffic metadata (such as source MAC addressing) as well as usage of network management protocols such as DHCP may be helpful in identifying hardware.
ICS	T0822		External Remote Services	Monitor for network traffic originating from unknown/unexpected systems.
Enterprise	T1008		Fallback Channels	Monitor network data for uncommon data flows, such as unexpected surges or other abnormal inbound/outbound patterns.
Enterprise	T1187		Forced Authentication	Monitor for SMB traffic on TCP ports 139, 445 and UDP port 137 and WebDAV traffic attempting to exit the network to unknown external systems.If attempts are detected, then investigate endpoint data sources to find the root cause.
Enterprise	T1200		Hardware Additions	Monitor for network traffic originating from unknown/unexpected hardware devices. Local network traffic metadata (such as source MAC addressing) as well as usage of network management protocols such as DHCP may be helpful in identifying hardware.
Enterprise	T1105		Ingress Tool Transfer	Monitor network data for uncommon data flows (e.g., a client sending significantly more data than it receives from a server). Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.
Enterprise	T1534		Internal Spearphishing	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.
ICS	T0883		Internet Accessible Device	Monitor for unexpected protocols to/from the Internet. While network traffic content and logon session metadata may directly identify a login event, new Internet-based network flows may also be a reliable indicator of this technique.
Enterprise	T1570		Lateral Tool Transfer	Monitor for network traffic originating from unknown/unexpected hardware devices. Local network traffic metadata (such as source MAC addressing) as well as usage of network management protocols such as DHCP may be helpful in identifying hardware.
ICS	T0867		Lateral Tool Transfer	Monitor for network traffic originating from unknown/unexpected hosts. Local network traffic metadata (such as source MAC addressing) as well as usage of network management protocols such as DHCP may be helpful in identifying hardware.
Mobile	T1430	.002	Location Tracking: Impersonate SS7 Nodes	Network carriers may be able to use firewalls, Intrusion Detection Systems (IDS), or Intrusion Prevention Systems (IPS) to detect and/or block SS7 exploitation.^[15] The CSRIC also suggests threat information sharing between telecommunications industry members.
Enterprise	T1112		Modify Registry	Remote access to the registry can be achieved via Windows API function RegConnectRegistry command line via reg.exe graphically via regedit.exe All of these behaviors call into the Windows API, which uses the NamedPipe WINREG over SMB to handle the protocol information. This network can be decoded with wireshark or a similar sensor, and can also be detected by hooking the API function. Analytic 1 - Remote Registry `source="Zeek:" (dest_port="445" AND proto_info.pipe="WINREG") OR (proto_info.function="Create" OR proto_info.function="SetValue")`
Enterprise	T1104		Multi-Stage Channels	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.
Enterprise	T1599		Network Boundary Bridging	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.
		.001	Network Address Translation Traversal	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.
Enterprise	T1498		Network Denial of Service	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.
		.001	Direct Network Flood	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.
		.002	Reflection Amplification	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.
Enterprise	T1046		Network Service Discovery	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious. It should be noted that when a host/ port/ service scan is performed from a compromised machine, a single machine makes multiple calls to other hosts in the network to identify live hosts and services. After compromising an initial machine, adversaries commonly attempt to laterally move across the network. The first step to attempt the Lateral Movement often involves conducting host identification, port and service scans on the internal network via the compromised machine using tools such as Nmap, Cobalt Strike, etc. Note: It should be noted that when a host/ port/ service scan is performed from a compromised machine, a single machine makes multiple calls to other hosts in the network to identify live hosts and services. This can be detected using the following query Analytic 1 - Identifying Port Scanning Activity `sourcetype='firewall_logs' dest_ip='internal_subnet' \| stats dc(dest_port) as pcount by src_ip \| where pcount >5`
Enterprise	T1095		Non-Application Layer Protocol	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.
Enterprise	T1571		Non-Standard Port	Monitor network data flows for unexpected patterns and metadata that may be indicative of a mismatch between protocol and utilized port.
Mobile	T1509		Non-Standard Port	Many properly configured firewalls may also naturally block command and control traffic over non-standard ports.
Enterprise	T1003		OS Credential Dumping	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.
		.006	DCSync	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.
Enterprise	T1566		Phishing	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.
		.001	Spearphishing Attachment	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.
		.002	Spearphishing Link	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.
		.003	Spearphishing via Service	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.
Mobile	T1660		Phishing	Enterprises may be able to detect anomalous traffic originating from mobile devices, which could indicate compromise.
Enterprise	T1598		Phishing for Information	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.
		.001	Spearphishing Service	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.
		.002	Spearphishing Attachment	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.
		.003	Spearphishing Link	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.
ICS	T0845		Program Upload	Monitor device communication patterns to identify irregular bulk transfers of data between the embedded ICS asset and other nodes within the network. Note these indicators are dependent on the profile of normal operations and the capabilities of the industrial automation protocols involved (e.g., partial program uploads).
Enterprise	T1572		Protocol Tunneling	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.
Enterprise	T1090		Proxy	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.
		.001	Internal Proxy	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.
		.002	External Proxy	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.
		.003	Multi-hop Proxy	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.
Mobile	T1604		Proxy Through Victim	Enterprises may be able to detect anomalous traffic originating from mobile devices, which could indicate compromise.
Enterprise	T1219		Remote Access Software	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.
Enterprise	T1563		Remote Service Session Hijacking	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.
		.001	SSH Hijacking	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.
		.002	RDP Hijacking	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious. RDP sessions may be split up into multiple flows and would therefore need to be aggregated. Anomaly detection using machine learning or other methods based on baselined RDP network flows may be a viable approach to alerting on potential RDP session hijacking.
Enterprise	T1021		Remote Services	Monitor network data for uncommon data flows that may be related to abuse of Valid Accounts to log into a service specifically designed to accept remote connections, such as RDP, telnet, SSH, and VNC. Note: Network Analysis frameworks such as Zeek can be used to capture, decode, and alert on network service protocols such as SSH and RDP. #Protocol 6 = TCP #Protocol 17 = UDP Analytic 1 - Suspicious Protocols`source="Zeek:" AND (port="636" AND protocol="6") OR (port="389" AND protocol="17")`
		.001	Remote Desktop Protocol	Monitor network traffic for uncommon data flows that may use Valid Accounts to log into a computer using the Remote Desktop Protocol (RDP). The Remote Desktop Protocol (RDP), built in to Microsoft operating systems, allows a user to remotely log in to the desktop of another host. It allows for interactive access of the running windows, and forwards key presses, mouse clicks, etc. Network administrators, power users, and end-users may use RDP for day-to-day operations. From an adversary’s perspective, RDP provides a means to laterally move to a new host. Determining which RDP connections correspond to adversary activity can be a difficult problem in highly dynamic environments, but will be useful in identifying the scope of a compromise.Remote Desktop can be detected in several ways Network connections to port 3389/tcp (assuming use of the default port) Packet capture analysis Detecting network connections from `mstsc.exe` Execution of the process `rdpclip.exe` Runs as the clipboard manager on the RDP target if clipboard sharing is enabled Analytic 1 `source="Zeek:" AND (port="3389") AND LogonType="10"`
		.002	SMB/Windows Admin Shares	Monitor network data for uncommon SMB data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious. Network Analysis frameworks such as Zeek can be used to capture, decode, and alert on SMB network flows. Notes: The logic for Implementation 1 is based around detecting on SMB write requests, which are often used by adversaries to move laterally to another host. Unlike SMB Reads, SMB Write requests typically require an additional level of access, resulting in less activity. Focusing on SMB Write activity narrows the field to looking at techniques associated with actively changing remote hosts, instead of passively reading files. The logic for Implementation 2 is based around detection of new processes that were created from a file written to an SMB share. First, a file is remotely written to a host via an SMB share; then, a variety of Execution techniques can be used to remotely establish execution of the file or script. To detect this behavior, look for files that are written to a host over SMB and then later run directly as a process or in the command line arguments. SMB File Writes and Remote Execution may happen normally in an environment, but the combination of the two behaviors is less frequent and more likely to indicate adversarial activity. Analytic 1 - SMB Write `source="*Zeek:SMB_Files" port="445" AND protocol="smb.write"`
		.006	Windows Remote Management	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious. Network Analysis frameworks such as Zeek can be used to capture, decode, and alert on RPC network flows. When a Windows Remote Management connection is opened, the client sends HTTP requests to port 5985 for HTTP or 5986 for HTTPS on the target host. Each HTTP(S) request to the URI "/wsman" is called, and other information is set in the headers. Depending on the operation, the HTTP method may vary (i.e., GET, POST, etc.). This analytic would detect Remote PowerShell, as well as other communications that rely on WinRM. Additionally, it outputs the executable on the client host, the connection information, and the hostname of the target host. Look for network connections to port 5985 and 5986. To really decipher what is going on, these outputs should be fed into something that can do packet analysis. Note: Traffic to the RPC Endpoint Mapper will always have the destination port of 135. Assuming success, RPC traffic will continue to the endpoint. The endpoint and the client both bind to dynamically assigned ports (on Windows, this is typically greater than 49152). The traffic between the client and endpoint can be detected by looking at traffic to 135 followed by traffic where the source and destination ports are at least 49152.
ICS	T0886		Remote Services	Monitor network data for uncommon data flows (e.g., time of day, unusual source/destination address) that may be related to abuse of Valid Accounts to log into a service specifically designed to accept remote connections, such as RDP, Telnet, SSH, and VNC.
ICS	T0846		Remote System Discovery	Monitor for new ICS protocol connections to existing assets or for device scanning (i.e., a host connecting to many devices) over ICS and enterprise protocols (e.g., ICMP, DCOM, WinRM). For added context on adversary enterprise procedures and background see Remote System Discovery.
ICS	T0888		Remote System Information Discovery	Monitor for new ICS protocol connections to existing assets or for device scanning (i.e., a host connecting to many devices) over ICS and enterprise protocols (e.g., ICMP, DCOM, WinRM).
Enterprise	T1496		Resource Hijacking	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.
ICS	T0848		Rogue Master	Monitor for network traffic originating from unknown/unexpected devices or addresses. Local network traffic metadata could be used to identify unexpected connections, including unknown/unexpected source MAC addresses connecting to ports associated with operational protocols. Also, network management protocols such as DHCP and ARP may be helpful in identifying unexpected devices.
Enterprise	T1053	.002	Scheduled Task/Job: At	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious. When AT.exe is used to remotely schedule tasks, Windows uses named pipes over SMB to communicate with the API on the remote machine. After authentication over SMB, the Named Pipe `ATSVC` is opened, over which the JobAdd function is called. On the remote host, the job files are created by the Task Scheduler and follow the convention `C:\Windows\System32\AT`. This pipe activity could be discovered with a network decoder, such as that in wireshark, that can inspect SMB traffic to identify the use of pipes. It could also be detected by looking for raw packet capture streams or from a custom sensor on the host that hooks the appropriate API functions. If no network or API level of visibility is possible, this traffic may inferred by looking at SMB connections over 445/tcp followed by the creation of files matching the pattern `C:\Windows\System32\AT\<job_id>`. To detect AT via network traffic, a sensor is needed that has the ability to extract and decode PCAP information. Specifically, it needs to properly decode SMB and the functions that are implemented over it via NamedPipes. If a sensor meets these criteria, then the PCAP data needs to search for instances of the command `JobAdd` over the pipe `ATSVC`, which is all implemented over Windows SMB 445/tcp. Analytic 1 - Remotely Scheduled Tasks via AT `source="Zeek:" (dest_port=445 AND proto_info.pipe="ATSVC") AND (proto_info.function="JobAdd")`
		.005	Scheduled Task/Job: Scheduled Task	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious. Look for RPC traffic after being mapped, which implies a destination port of at least 49152. If network inspection is available via packet captures or a NIDS, then traffic through the `ITaskSchedulerService` interface can be detected. Microsoft has a list of the possible methods that are implemented for the `ITaskSchedulerService` interface, which may be useful in differentiating read and query operations from creations and modifications. When scheduled tasks are created remotely, Windows uses RPC (135/tcp) to communicate with the Task Scheduler on the remote machine. Once an RPC connection is established, the client communicates with the Scheduled Tasks endpoint, which runs within the service group netsvcs. With packet capture and the right packet decoders or byte-stream based signatures, remote invocations of these functions can be identified.Certain strings can be identifiers of the schtasks, by looking up the interface UUID of ITaskSchedulerService in different formats UUID `86d35949-83c9-4044-b424-db363231fd0c` (decoded) Hex `49 59 d3 86 c9 83 44 40 b4 24 db 36 32 31 fd 0c` (raw) ASCII `IYD@$621` (printable bytes only) This identifier is present three times during the RPC request phase. Any sensor that has access to the byte code as raw, decoded, or ASCII could implement an analytic.
Enterprise	T1029		Scheduled Transfer	Monitor for network traffic originating from unknown/unexpected hardware devices. Local network traffic metadata (such as source MAC addressing) as well as usage of network management protocols such as DHCP may be helpful in identifying hardware.
Enterprise	T1505		Server Software Component	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.
		.003	Web Shell	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.
ICS	T0856		Spoof Reporting Message	Various techniques enable spoofing a reporting message. Consider monitoring for Rogue Master and Adversary-in-the-Middle activity which may precede this technique.
ICS	T0869		Standard Application Layer Protocol	Monitor and analyze traffic flows that do not follow the expected protocol standards and traffic flows (e.g., extraneous packets that do not belong to established flows , or gratuitous or anomalous traffic patterns). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g., monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
Enterprise	T1033		System Owner/User Discovery	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.
Enterprise	T1569	.002	System Services: Service Execution	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.
Enterprise	T1205		Traffic Signaling	Monitor and analyze network flows associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, or gratuitous or anomalous traffic patterns). Consider analyzing newly constructed network connections that are sent or received by untrusted hosts, unexpcted hardware devices, or other uncommon data flows.
		.001	Port Knocking	Monitor and analyze network flows associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, or gratuitous or anomalous traffic patterns). Consider analyzing newly constructed network connections that are sent or received by untrusted hosts, unexpcted hardware devices, or other uncommon data flows.
ICS	T0864		Transient Cyber Asset	Monitor for network traffic originating from unknown/unexpected hardware devices. Local network traffic metadata (such as source MAC addressing) may be helpful in identifying transient assets.
ICS	T0855		Unauthorized Command Message	Monitor for new or unexpected connections to controllers, which could indicate an Unauthorized Command Message being sent via Rogue Master.
Enterprise	T1102		Web Service	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.
		.001	Dead Drop Resolver	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.
		.002	Bidirectional Communication	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.
		.003	One-Way Communication	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.
ICS	T0860		Wireless Compromise	New or irregular network traffic flows may indicate potentially unwanted devices or sessions on wireless networks. In Wi-Fi networks monitor for changes such as rogue access points or low signal strength, indicating a device is further away from the access point then expected and changes in the physical layer signal.^[16] ^[17] Network traffic content will provide important context, such as hardware (e.g., MAC) addresses, user accounts, and types of messages sent.
ICS	T0887		Wireless Sniffing	Purely passive network sniffing cannot be detected effectively. In cases where the adversary interacts with the wireless network (e.g., joining a Wi-Fi network) detection may be possible. Monitor for new or irregular network traffic flows which may indicate potentially unwanted devices or sessions on wireless networks. In Wi-Fi networks monitor for changes such as rogue access points or low signal strength, indicating a device is further away from the access point then expected and changes in the physical layer signal.^[16] ^[17] Network traffic content will provide important context, such as hardware (e.g., MAC) addresses, user accounts, and types of messages sent.

Network Traffic

Data Components

Network Traffic: Network Connection Creation

Network Traffic: Network Connection Creation

Network Traffic: Network Traffic Content

Network Traffic: Network Traffic Content

Network Traffic: Network Traffic Flow

Network Traffic: Network Traffic Flow

References