The adversary is trying to steal account names and passwords.
Credential Access consists of techniques for stealing credentials like account names and passwords. Techniques used to get credentials include keylogging or credential dumping. Using legitimate credentials can give adversaries access to systems, make them harder to detect, and provide the opportunity to create more accounts to help achieve their goals.
|Adversaries may attempt to position themselves between two or more networked devices using an adversary-in-the-middle (AiTM) technique to support follow-on behaviors such as Network Sniffing, Transmitted Data Manipulation, or replay attacks (Exploitation for Credential Access). By abusing features of common networking protocols that can determine the flow of network traffic (e.g. ARP, DNS, LLMNR, etc.), adversaries may force a device to communicate through an adversary controlled system so they can collect information or perform additional actions.
|LLMNR/NBT-NS Poisoning and SMB Relay
|By responding to LLMNR/NBT-NS network traffic, adversaries may spoof an authoritative source for name resolution to force communication with an adversary controlled system. This activity may be used to collect or relay authentication materials.
|ARP Cache Poisoning
|Adversaries may poison Address Resolution Protocol (ARP) caches to position themselves between the communication of two or more networked devices. This activity may be used to enable follow-on behaviors such as Network Sniffing or Transmitted Data Manipulation.
|Adversaries may redirect network traffic to adversary-owned systems by spoofing Dynamic Host Configuration Protocol (DHCP) traffic and acting as a malicious DHCP server on the victim network. By achieving the adversary-in-the-middle (AiTM) position, adversaries may collect network communications, including passed credentials, especially those sent over insecure, unencrypted protocols. This may also enable follow-on behaviors such as Network Sniffing or Transmitted Data Manipulation.
|Adversaries may use brute force techniques to gain access to accounts when passwords are unknown or when password hashes are obtained. Without knowledge of the password for an account or set of accounts, an adversary may systematically guess the password using a repetitive or iterative mechanism. Brute forcing passwords can take place via interaction with a service that will check the validity of those credentials or offline against previously acquired credential data, such as password hashes.
|Adversaries with no prior knowledge of legitimate credentials within the system or environment may guess passwords to attempt access to accounts. Without knowledge of the password for an account, an adversary may opt to systematically guess the password using a repetitive or iterative mechanism. An adversary may guess login credentials without prior knowledge of system or environment passwords during an operation by using a list of common passwords. Password guessing may or may not take into account the target's policies on password complexity or use policies that may lock accounts out after a number of failed attempts.
|Adversaries may use password cracking to attempt to recover usable credentials, such as plaintext passwords, when credential material such as password hashes are obtained. OS Credential Dumping can be used to obtain password hashes, this may only get an adversary so far when Pass the Hash is not an option. Further, adversaries may leverage Data from Configuration Repository in order to obtain hashed credentials for network devices.
|Adversaries may use a single or small list of commonly used passwords against many different accounts to attempt to acquire valid account credentials. Password spraying uses one password (e.g. 'Password01'), or a small list of commonly used passwords, that may match the complexity policy of the domain. Logins are attempted with that password against many different accounts on a network to avoid account lockouts that would normally occur when brute forcing a single account with many passwords.
|Adversaries may use credentials obtained from breach dumps of unrelated accounts to gain access to target accounts through credential overlap. Occasionally, large numbers of username and password pairs are dumped online when a website or service is compromised and the user account credentials accessed. The information may be useful to an adversary attempting to compromise accounts by taking advantage of the tendency for users to use the same passwords across personal and business accounts.
|Credentials from Password Stores
|Adversaries may search for common password storage locations to obtain user credentials. Passwords are stored in several places on a system, depending on the operating system or application holding the credentials. There are also specific applications and services that store passwords to make them easier for users to manage and maintain, such as password managers and cloud secrets vaults. Once credentials are obtained, they can be used to perform lateral movement and access restricted information.
|Adversaries may acquire credentials from Keychain. Keychain (or Keychain Services) is the macOS credential management system that stores account names, passwords, private keys, certificates, sensitive application data, payment data, and secure notes. There are three types of Keychains: Login Keychain, System Keychain, and Local Items (iCloud) Keychain. The default Keychain is the Login Keychain, which stores user passwords and information. The System Keychain stores items accessed by the operating system, such as items shared among users on a host. The Local Items (iCloud) Keychain is used for items synced with Apple’s iCloud service.
|An adversary may obtain root access (allowing them to read securityd’s memory), then they can scan through memory to find the correct sequence of keys in relatively few tries to decrypt the user’s logon keychain. This provides the adversary with all the plaintext passwords for users, WiFi, mail, browsers, certificates, secure notes, etc.
|Credentials from Web Browsers
|Adversaries may acquire credentials from web browsers by reading files specific to the target browser. Web browsers commonly save credentials such as website usernames and passwords so that they do not need to be entered manually in the future. Web browsers typically store the credentials in an encrypted format within a credential store; however, methods exist to extract plaintext credentials from web browsers.
|Windows Credential Manager
|Adversaries may acquire credentials from the Windows Credential Manager. The Credential Manager stores credentials for signing into websites, applications, and/or devices that request authentication through NTLM or Kerberos in Credential Lockers (previously known as Windows Vaults).
|Adversaries may acquire user credentials from third-party password managers. Password managers are applications designed to store user credentials, normally in an encrypted database. Credentials are typically accessible after a user provides a master password that unlocks the database. After the database is unlocked, these credentials may be copied to memory. These databases can be stored as files on disk.
|Cloud Secrets Management Stores
|Adversaries may acquire credentials from cloud-native secret management solutions such as AWS Secrets Manager, GCP Secret Manager, Azure Key Vault, and Terraform Vault.
|Exploitation for Credential Access
|Adversaries may exploit software vulnerabilities in an attempt to collect credentials. Exploitation of a software vulnerability occurs when an adversary takes advantage of a programming error in a program, service, or within the operating system software or kernel itself to execute adversary-controlled code.
|Adversaries may gather credential material by invoking or forcing a user to automatically provide authentication information through a mechanism in which they can intercept.
|Forge Web Credentials
|Adversaries may forge credential materials that can be used to gain access to web applications or Internet services. Web applications and services (hosted in cloud SaaS environments or on-premise servers) often use session cookies, tokens, or other materials to authenticate and authorize user access.
|Adversaries may forge web cookies that can be used to gain access to web applications or Internet services. Web applications and services (hosted in cloud SaaS environments or on-premise servers) often use session cookies to authenticate and authorize user access.
An adversary may forge SAML tokens with any permissions claims and lifetimes if they possess a valid SAML token-signing certificate. The default lifetime of a SAML token is one hour, but the validity period can be specified in the
NotOnOrAfter value of the
conditions ... element in a token. This value can be changed using the
AccessTokenLifetime in a
LifetimeTokenPolicy. Forged SAML tokens enable adversaries to authenticate across services that use SAML 2.0 as an SSO (single sign-on) mechanism.
|Adversaries may use methods of capturing user input to obtain credentials or collect information. During normal system usage, users often provide credentials to various different locations, such as login pages/portals or system dialog boxes. Input capture mechanisms may be transparent to the user (e.g. Credential API Hooking) or rely on deceiving the user into providing input into what they believe to be a genuine service (e.g. Web Portal Capture).
|Adversaries may log user keystrokes to intercept credentials as the user types them. Keylogging is likely to be used to acquire credentials for new access opportunities when OS Credential Dumping efforts are not effective, and may require an adversary to intercept keystrokes on a system for a substantial period of time before credentials can be successfully captured. In order to increase the likelihood of capturing credentials quickly, an adversary may also perform actions such as clearing browser cookies to force users to reauthenticate to systems.
|GUI Input Capture
|Adversaries may mimic common operating system GUI components to prompt users for credentials with a seemingly legitimate prompt. When programs are executed that need additional privileges than are present in the current user context, it is common for the operating system to prompt the user for proper credentials to authorize the elevated privileges for the task (ex: Bypass User Account Control).
|Web Portal Capture
|Adversaries may install code on externally facing portals, such as a VPN login page, to capture and transmit credentials of users who attempt to log into the service. For example, a compromised login page may log provided user credentials before logging the user in to the service.
|Credential API Hooking
|Adversaries may hook into Windows application programming interface (API) functions to collect user credentials. Malicious hooking mechanisms may capture API calls that include parameters that reveal user authentication credentials. Unlike Keylogging, this technique focuses specifically on API functions that include parameters that reveal user credentials. Hooking involves redirecting calls to these functions and can be implemented via:
|Modify Authentication Process
|Adversaries may modify authentication mechanisms and processes to access user credentials or enable otherwise unwarranted access to accounts. The authentication process is handled by mechanisms, such as the Local Security Authentication Server (LSASS) process and the Security Accounts Manager (SAM) on Windows, pluggable authentication modules (PAM) on Unix-based systems, and authorization plugins on MacOS systems, responsible for gathering, storing, and validating credentials. By modifying an authentication process, an adversary may be able to authenticate to a service or system without using Valid Accounts.
|Domain Controller Authentication
|Adversaries may patch the authentication process on a domain controller to bypass the typical authentication mechanisms and enable access to accounts.
|Password Filter DLL
|Adversaries may register malicious password filter dynamic link libraries (DLLs) into the authentication process to acquire user credentials as they are validated.
|Pluggable Authentication Modules
Adversaries may modify pluggable authentication modules (PAM) to access user credentials or enable otherwise unwarranted access to accounts. PAM is a modular system of configuration files, libraries, and executable files which guide authentication for many services. The most common authentication module is
pam_unix.so, which retrieves, sets, and verifies account authentication information in
|Network Device Authentication
|Adversaries may use Patch System Image to hard code a password in the operating system, thus bypassing of native authentication mechanisms for local accounts on network devices.
An adversary may abuse Active Directory authentication encryption properties to gain access to credentials on Windows systems. The
AllowReversiblePasswordEncryption property specifies whether reversible password encryption for an account is enabled or disabled. By default this property is disabled (instead storing user credentials as the output of one-way hashing functions) and should not be enabled unless legacy or other software require it.
|Adversaries may disable or modify multi-factor authentication (MFA) mechanisms to enable persistent access to compromised accounts.
|Adversaries may patch, modify, or otherwise backdoor cloud authentication processes that are tied to on-premises user identities in order to bypass typical authentication mechanisms, access credentials, and enable persistent access to accounts.
|Network Provider DLL
Adversaries may register malicious network provider dynamic link libraries (DLLs) to capture cleartext user credentials during the authentication process. Network provider DLLs allow Windows to interface with specific network protocols and can also support add-on credential management functions. During the logon process, Winlogon (the interactive logon module) sends credentials to the local
mpnotify.exe process via RPC. The
mpnotify.exe process then shares the credentials in cleartext with registered credential managers when notifying that a logon event is happening.
|Multi-Factor Authentication Interception
|Adversaries may target multi-factor authentication (MFA) mechanisms, (i.e., smart cards, token generators, etc.) to gain access to credentials that can be used to access systems, services, and network resources. Use of MFA is recommended and provides a higher level of security than usernames and passwords alone, but organizations should be aware of techniques that could be used to intercept and bypass these security mechanisms.
|Multi-Factor Authentication Request Generation
|Adversaries may attempt to bypass multi-factor authentication (MFA) mechanisms and gain access to accounts by generating MFA requests sent to users.
|Adversaries may sniff network traffic to capture information about an environment, including authentication material passed over the network. Network sniffing refers to using the network interface on a system to monitor or capture information sent over a wired or wireless connection. An adversary may place a network interface into promiscuous mode to passively access data in transit over the network, or use span ports to capture a larger amount of data.
|OS Credential Dumping
|Adversaries may attempt to dump credentials to obtain account login and credential material, normally in the form of a hash or a clear text password, from the operating system and software. Credentials can then be used to perform Lateral Movement and access restricted information.
|Adversaries may attempt to access credential material stored in the process memory of the Local Security Authority Subsystem Service (LSASS). After a user logs on, the system generates and stores a variety of credential materials in LSASS process memory. These credential materials can be harvested by an administrative user or SYSTEM and used to conduct Lateral Movement using Use Alternate Authentication Material.
|Security Account Manager
Adversaries may attempt to extract credential material from the Security Account Manager (SAM) database either through in-memory techniques or through the Windows Registry where the SAM database is stored. The SAM is a database file that contains local accounts for the host, typically those found with the
net user command. Enumerating the SAM database requires SYSTEM level access.
Adversaries may attempt to access or create a copy of the Active Directory domain database in order to steal credential information, as well as obtain other information about domain members such as devices, users, and access rights. By default, the NTDS file (NTDS.dit) is located in
%SystemRoot%\NTDS\Ntds.dit of a domain controller.
Adversaries with SYSTEM access to a host may attempt to access Local Security Authority (LSA) secrets, which can contain a variety of different credential materials, such as credentials for service accounts. LSA secrets are stored in the registry at
HKEY_LOCAL_MACHINE\SECURITY\Policy\Secrets. LSA secrets can also be dumped from memory.
|Cached Domain Credentials
|Adversaries may attempt to access cached domain credentials used to allow authentication to occur in the event a domain controller is unavailable.
|Adversaries may attempt to access credentials and other sensitive information by abusing a Windows Domain Controller's application programming interface (API) to simulate the replication process from a remote domain controller using a technique called DCSync.
Adversaries may gather credentials from the proc filesystem or
/proc. The proc filesystem is a pseudo-filesystem used as an interface to kernel data structures for Linux based systems managing virtual memory. For each process, the
/proc/<PID>/maps file shows how memory is mapped within the process’s virtual address space. And
/proc/<PID>/mem, exposed for debugging purposes, provides access to the process’s virtual address space.
|/etc/passwd and /etc/shadow
Adversaries may attempt to dump the contents of
/etc/shadow to enable offline password cracking. Most modern Linux operating systems use a combination of
/etc/shadow to store user account information including password hashes in
/etc/shadow. By default,
/etc/shadow is only readable by the root user.
|Steal Application Access Token
|Adversaries can steal application access tokens as a means of acquiring credentials to access remote systems and resources.
|Steal or Forge Authentication Certificates
|Adversaries may steal or forge certificates used for authentication to access remote systems or resources. Digital certificates are often used to sign and encrypt messages and/or files. Certificates are also used as authentication material. For example, Azure AD device certificates and Active Directory Certificate Services (AD CS) certificates bind to an identity and can be used as credentials for domain accounts.
|Steal or Forge Kerberos Tickets
|Adversaries may attempt to subvert Kerberos authentication by stealing or forging Kerberos tickets to enable Pass the Ticket. Kerberos is an authentication protocol widely used in modern Windows domain environments. In Kerberos environments, referred to as "realms", there are three basic participants: client, service, and Key Distribution Center (KDC). Clients request access to a service and through the exchange of Kerberos tickets, originating from KDC, they are granted access after having successfully authenticated. The KDC is responsible for both authentication and ticket granting. Adversaries may attempt to abuse Kerberos by stealing tickets or forging tickets to enable unauthorized access.
|Adversaries who have the KRBTGT account password hash may forge Kerberos ticket-granting tickets (TGT), also known as a golden ticket. Golden tickets enable adversaries to generate authentication material for any account in Active Directory.
|Adversaries who have the password hash of a target service account (e.g. SharePoint, MSSQL) may forge Kerberos ticket granting service (TGS) tickets, also known as silver tickets. Kerberos TGS tickets are also known as service tickets.
|Adversaries may abuse a valid Kerberos ticket-granting ticket (TGT) or sniff network traffic to obtain a ticket-granting service (TGS) ticket that may be vulnerable to Brute Force.
|Adversaries may reveal credentials of accounts that have disabled Kerberos preauthentication by Password Cracking Kerberos messages.
|Steal Web Session Cookie
|An adversary may steal web application or service session cookies and use them to gain access to web applications or Internet services as an authenticated user without needing credentials. Web applications and services often use session cookies as an authentication token after a user has authenticated to a website.
|Adversaries may search compromised systems to find and obtain insecurely stored credentials. These credentials can be stored and/or misplaced in many locations on a system, including plaintext files (e.g. Bash History), operating system or application-specific repositories (e.g. Credentials in Registry), or other specialized files/artifacts (e.g. Private Keys).
|Credentials In Files
|Adversaries may search local file systems and remote file shares for files containing insecurely stored credentials. These can be files created by users to store their own credentials, shared credential stores for a group of individuals, configuration files containing passwords for a system or service, or source code/binary files containing embedded passwords.
|Credentials in Registry
|Adversaries may search the Registry on compromised systems for insecurely stored credentials. The Windows Registry stores configuration information that can be used by the system or other programs. Adversaries may query the Registry looking for credentials and passwords that have been stored for use by other programs or services. Sometimes these credentials are used for automatic logons.
Adversaries may search the bash command history on compromised systems for insecurely stored credentials. Bash keeps track of the commands users type on the command-line with the "history" utility. Once a user logs out, the history is flushed to the user’s
.bash_history file. For each user, this file resides at the same location:
~/.bash_history. Typically, this file keeps track of the user’s last 500 commands. Users often type usernames and passwords on the command-line as parameters to programs, which then get saved to this file when they log out. Adversaries can abuse this by looking through the file for potential credentials.
|Adversaries may search for private key certificate files on compromised systems for insecurely stored credentials. Private cryptographic keys and certificates are used for authentication, encryption/decryption, and digital signatures. Common key and certificate file extensions include: .key, .pgp, .gpg, .ppk., .p12, .pem, .pfx, .cer, .p7b, .asc.
|Cloud Instance Metadata API
|Adversaries may attempt to access the Cloud Instance Metadata API to collect credentials and other sensitive data.
|Group Policy Preferences
|Adversaries may attempt to find unsecured credentials in Group Policy Preferences (GPP). GPP are tools that allow administrators to create domain policies with embedded credentials. These policies allow administrators to set local accounts.
|Adversaries may gather credentials via APIs within a containers environment. APIs in these environments, such as the Docker API and Kubernetes APIs, allow a user to remotely manage their container resources and cluster components.
|Adversaries may directly collect unsecured credentials stored or passed through user communication services. Credentials may be sent and stored in user chat communication applications such as email, chat services like Slack or Teams, collaboration tools like Jira or Trello, and any other services that support user communication. Users may share various forms of credentials (such as usernames and passwords, API keys, or authentication tokens) on private or public corporate internal communications channels.