|T1134||Access Token Manipulation|
Windows uses access tokens to determine the ownership of a running process. A user can manipulate access tokens to make a running process appear as though it belongs to someone other than the user that started the process. When this occurs, the process also takes on the security context associated with the new token. For example, Microsoft promotes the use of access tokens as a security best practice. Administrators should log in as a standard user but run their tools with administrator privileges using the built-in access token manipulation command
Some security tools inspect files with static signatures to determine if they are known malicious. Adversaries may add data to files to increase the size beyond what security tools are capable of handling or to change the file hash to avoid hash-based blacklists.
Windows Background Intelligent Transfer Service (BITS) is a low-bandwidth, asynchronous file transfer mechanism exposed through Component Object Model (COM). BITS is commonly used by updaters, messengers, and other applications preferred to operate in the background (using available idle bandwidth) without interrupting other networked applications. File transfer tasks are implemented as BITS jobs, which contain a queue of one or more file operations.
|T1088||Bypass User Account Control|
Windows User Account Control (UAC) allows a program to elevate its privileges to perform a task under administrator-level permissions by prompting the user for confirmation. The impact to the user ranges from denying the operation under high enforcement to allowing the user to perform the action if they are in the local administrators group and click through the prompt or allowing them to enter an administrator password to complete the action.
|T1146||Clear Command History|
macOS and Linux both keep track of the commands users type in their terminal so that users can easily remember what they've done. These logs can be accessed in a few different ways. While logged in, this command history is tracked in a file pointed to by the environment variable
The Microsoft Connection Manager Profile Installer (CMSTP.exe) is a command-line program used to install Connection Manager service profiles. CMSTP.exe accepts an installation information file (INF) as a parameter and installs a service profile leveraged for remote access connections.
Code signing provides a level of authenticity on a binary from the developer and a guarantee that the binary has not been tampered with. However, adversaries are known to use code signing certificates to masquerade malware and tools as legitimate binaries . The certificates used during an operation may be created, forged, or stolen by the adversary.
|T1500||Compile After Delivery|
Adversaries may attempt to make payloads difficult to discover and analyze by delivering files to victims as uncompiled code. Similar to Obfuscated Files or Information, text-based source code files may subvert analysis and scrutiny from protections targeting executables/binaries. These payloads will need to be compiled before execution; typically via native utilities such as csc.exe or GCC/MinGW.
|T1223||Compiled HTML File|
Compiled HTML files (.chm) are commonly distributed as part of the Microsoft HTML Help system. CHM files are compressed compilations of various content such as HTML documents, images, and scripting/web related programming languages such VBA, JScript, Java, and ActiveX. CHM content is displayed using underlying components of the Internet Explorer browser loaded by the HTML Help executable program (hh.exe).
Some adversaries may employ sophisticated means to compromise computer components and install malicious firmware that will execute adversary code outside of the operating system and main system firmware or BIOS. This technique may be similar to System Firmware but conducted upon other system components that may not have the same capability or level of integrity checking. Malicious device firmware could provide both a persistent level of access to systems despite potential typical failures to maintain access and hard disk re-images, as well as a way to evade host software-based defenses and integrity checks.
|T1122||Component Object Model Hijacking|
The Component Object Model (COM) is a system within Windows to enable interaction between software components through the operating system. Adversaries can use this system to insert malicious code that can be executed in place of legitimate software through hijacking the COM references and relationships as a means for persistence. Hijacking a COM object requires a change in the Windows Registry to replace a reference to a legitimate system component which may cause that component to not work when executed. When that system component is executed through normal system operation the adversary's code will be executed instead. An adversary is likely to hijack objects that are used frequently enough to maintain a consistent level of persistence, but are unlikely to break noticeable functionality within the system as to avoid system instability that could lead to detection.
|T1196||Control Panel Items|
Windows Control Panel items are utilities that allow users to view and adjust computer settings. Control Panel items are registered executable (.exe) or Control Panel (.cpl) files, the latter are actually renamed dynamic-link library (.dll) files that export a CPlApplet function. Control Panel items can be executed directly from the command line, programmatically via an application programming interface (API) call, or by simply double-clicking the file.
DCShadow is a method of manipulating Active Directory (AD) data, including objects and schemas, by registering (or reusing an inactive registration) and simulating the behavior of a Domain Controller (DC). Once registered, a rogue DC may be able to inject and replicate changes into AD infrastructure for any domain object, including credentials and keys.
|T1140||Deobfuscate/Decode Files or Information|
Adversaries may use Obfuscated Files or Information to hide artifacts of an intrusion from analysis. They may require separate mechanisms to decode or deobfuscate that information depending on how they intend to use it. Methods for doing that include built-in functionality of malware, Scripting, PowerShell, or by using utilities present on the system.
|T1089||Disabling Security Tools|
Adversaries may disable security tools to avoid possible detection of their tools and activities. This can take the form of killing security software or event logging processes, deleting Registry keys so that tools do not start at run time, or other methods to interfere with security scanning or event reporting.
|T1038||DLL Search Order Hijacking|
Windows systems use a common method to look for required DLLs to load into a program. Adversaries may take advantage of the Windows DLL search order and programs that ambiguously specify DLLs to gain privilege escalation and persistence.
Programs may specify DLLs that are loaded at runtime. Programs that improperly or vaguely specify a required DLL may be open to a vulnerability in which an unintended DLL is loaded. Side-loading vulnerabilities specifically occur when Windows Side-by-Side (WinSxS) manifests are not explicit enough about characteristics of the DLL to be loaded. Adversaries may take advantage of a legitimate program that is vulnerable to side-loading to load a malicious DLL.
Execution guardrails constrain execution or actions based on adversary supplied environment specific conditions that are expected to be present on the target.
|T1211||Exploitation for Defense Evasion|
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. Vulnerabilities may exist in defensive security software that can be used to disable or circumvent them.
|T1181||Extra Window Memory Injection|
Before creating a window, graphical Windows-based processes must prescribe to or register a windows class, which stipulate appearance and behavior (via windows procedures, which are functions that handle input/output of data). Registration of new windows classes can include a request for up to 40 bytes of extra window memory (EWM) to be appended to the allocated memory of each instance of that class. This EWM is intended to store data specific to that window and has specific application programming interface (API) functions to set and get its value.
Malware, tools, or other non-native files dropped or created on a system by an adversary may leave traces behind as to what was done within a network and how. Adversaries may remove these files over the course of an intrusion to keep their footprint low or remove them at the end as part of the post-intrusion cleanup process.
|T1222||File Permissions Modification|
File permissions are commonly managed by discretionary access control lists (DACLs) specified by the file owner. File DACL implementation may vary by platform, but generally explicitly designate which users/groups can perform which actions (ex: read, write, execute, etc.).
|T1006||File System Logical Offsets|
Windows allows programs to have direct access to logical volumes. Programs with direct access may read and write files directly from the drive by analyzing file system data structures. This technique bypasses Windows file access controls as well as file system monitoring tools.
In macOS and OS X, when applications or programs are downloaded from the internet, there is a special attribute set on the file called
|T1484||Group Policy Modification|
Adversaries may modify Group Policy Objects (GPOs) to subvert the intended discretionary access controls for a domain, usually with the intention of escalating privileges on the domain.
|T1158||Hidden Files and Directories|
To prevent normal users from accidentally changing special files on a system, most operating systems have the concept of a ‘hidden’ file. These files don’t show up when a user browses the file system with a GUI or when using normal commands on the command line. Users must explicitly ask to show the hidden files either via a series of Graphical User Interface (GUI) prompts or with command line switches (
Every user account in macOS has a userID associated with it. When creating a user, you can specify the userID for that account. There is a property value in
The configurations for how applications run on macOS and OS X are listed in property list (plist) files. One of the tags in these files can be
|T1183||Image File Execution Options Injection|
Image File Execution Options (IFEO) enable a developer to attach a debugger to an application. When a process is created, a debugger present in an application’s IFEO will be prepended to the application’s name, effectively launching the new process under the debugger (e.g., "C:\dbg\ntsd.exe -g notepad.exe").
An adversary may attempt to block indicators or events typically captured by sensors from being gathered and analyzed. This could include modifying sensor settings stored in configuration files and/or Registry keys to disable or maliciously redirect event telemetry.
|T1066||Indicator Removal from Tools|
If a malicious tool is detected and quarantined or otherwise curtailed, an adversary may be able to determine why the malicious tool was detected (the indicator), modify the tool by removing the indicator, and use the updated version that is no longer detected by the target's defensive systems or subsequent targets that may use similar systems.
|T1070||Indicator Removal on Host|
Adversaries may delete or alter generated artifacts on a host system, including logs and potentially captured files such as quarantined malware. Locations and format of logs will vary, but typical organic system logs are captured as Windows events or Linux/macOS files such as Bash History and /var/log/* .
|T1202||Indirect Command Execution|
Various Windows utilities may be used to execute commands, possibly without invoking cmd. For example, Forfiles, the Program Compatibility Assistant (pcalua.exe), components of the Windows Subsystem for Linux (WSL), as well as other utilities may invoke the execution of programs and commands from a Command-Line Interface, Run window, or via scripts.
|T1130||Install Root Certificate|
Root certificates are used in public key cryptography to identify a root certificate authority (CA). When a root certificate is installed, the system or application will trust certificates in the root's chain of trust that have been signed by the root certificate. Certificates are commonly used for establishing secure TLS/SSL communications within a web browser. When a user attempts to browse a website that presents a certificate that is not trusted an error message will be displayed to warn the user of the security risk. Depending on the security settings, the browser may not allow the user to establish a connection to the website.
InstallUtil is a command-line utility that allows for installation and uninstallation of resources by executing specific installer components specified in .NET binaries. InstallUtil is located in the .NET directories on a Windows system:
Launchctl controls the macOS launchd process which handles things like launch agents and launch daemons, but can execute other commands or programs itself. Launchctl supports taking subcommands on the command-line, interactively, or even redirected from standard input. By loading or reloading launch agents or launch daemons, adversaries can install persistence or execute changes they made . Running a command from launchctl is as simple as
As of OS X 10.8, mach-O binaries introduced a new header called LC_MAIN that points to the binary’s entry point for execution. Previously, there were two headers to achieve this same effect: LC_THREAD and LC_UNIXTHREAD . The entry point for a binary can be hijacked so that initial execution flows to a malicious addition (either another section or a code cave) and then goes back to the initial entry point so that the victim doesn’t know anything was different . By modifying a binary in this way, application whitelisting can be bypassed because the file name or application path is still the same.
Masquerading occurs when the name or location of an executable, legitimate or malicious, is manipulated or abused for the sake of evading defenses and observation. Several different variations of this technique have been observed.
Adversaries may interact with the Windows Registry to hide configuration information within Registry keys, remove information as part of cleaning up, or as part of other techniques to aid in Persistence and Execution.
Mshta.exe is a utility that executes Microsoft HTML Applications (HTA). HTA files have the file extension
|T1126||Network Share Connection Removal|
Windows shared drive and Windows Admin Shares connections can be removed when no longer needed. Net is an example utility that can be used to remove network share connections with the
|T1096||NTFS File Attributes|
Every New Technology File System (NTFS) formatted partition contains a Master File Table (MFT) that maintains a record for every file/directory on the partition. Within MFT entries are file attributes, such as Extended Attributes (EA) and Data [known as Alternate Data Streams (ADSs) when more than one Data attribute is present], that can be used to store arbitrary data (and even complete files).
|T1027||Obfuscated Files or Information|
Adversaries may attempt to make an executable or file difficult to discover or analyze by encrypting, encoding, or otherwise obfuscating its contents on the system or in transit. This is common behavior that can be used across different platforms and the network to evade defenses.
Property list (plist) files contain all of the information that macOS and OS X uses to configure applications and services. These files are UTF-8 encoded and formatted like XML documents via a series of keys surrounded by < >. They detail when programs should execute, file paths to the executables, program arguments, required OS permissions, and many others. plists are located in certain locations depending on their purpose such as
Port Knocking is a well-established method used by both defenders and adversaries to hide open ports from access. To enable a port, an adversary sends a series of packets with certain characteristics before the port will be opened. Usually this series of packets consists of attempted connections to a predefined sequence of closed ports, but can involve unusual flags, specific strings or other unique characteristics. After the sequence is completed, opening a port is often accomplished by the host based firewall, but could also be implemented by custom software.
Windows Transactional NTFS (TxF) was introduced in Vista as a method to perform safe file operations. To ensure data integrity, TxF enables only one transacted handle to write to a file at a given time. Until the write handle transaction is terminated, all other handles are isolated from the writer and may only read the committed version of the file that existed at the time the handle was opened. To avoid corruption, TxF performs an automatic rollback if the system or application fails during a write transaction.
Process hollowing occurs when a process is created in a suspended state then its memory is unmapped and replaced with malicious code. Similar to Process Injection, execution of the malicious code is masked under a legitimate process and may evade defenses and detection analysis.
Process injection is a method of executing arbitrary code in the address space of a separate live process. Running code in the context of another process may allow access to the process's memory, system/network resources, and possibly elevated privileges. Execution via process injection may also evade detection from security products since the execution is masked under a legitimate process.
Adversaries may use more than one remote access tool with varying command and control protocols as a hedge against detection. If one type of tool is detected and blocked or removed as a response but the organization did not gain a full understanding of the adversary's tools and access, then the adversary will be able to retain access to the network. Adversaries may also attempt to gain access to Valid Accounts to use External Remote Services such as external VPNs as a way to maintain access despite interruptions to remote access tools deployed within a target network.
Regsvcs and Regasm are Windows command-line utilities that are used to register .NET Component Object Model (COM) assemblies. Both are digitally signed by Microsoft.
Regsvr32.exe is a command-line program used to register and unregister object linking and embedding controls, including dynamic link libraries (DLLs), on Windows systems. Regsvr32.exe can be used to execute arbitrary binaries.
Rootkits are programs that hide the existence of malware by intercepting (i.e., Hooking) and modifying operating system API calls that supply system information. Rootkits or rootkit enabling functionality may reside at the user or kernel level in the operating system or lower, to include a Hypervisor, Master Boot Record, or the System Firmware.
The rundll32.exe program can be called to execute an arbitrary binary. Adversaries may take advantage of this functionality to proxy execution of code to avoid triggering security tools that may not monitor execution of the rundll32.exe process because of whitelists or false positives from Windows using rundll32.exe for normal operations.
Adversaries may use scripts to aid in operations and perform multiple actions that would otherwise be manual. Scripting is useful for speeding up operational tasks and reducing the time required to gain access to critical resources. Some scripting languages may be used to bypass process monitoring mechanisms by directly interacting with the operating system at an API level instead of calling other programs. Common scripting languages for Windows include VBScript and PowerShell but could also be in the form of command-line batch scripts.
|T1218||Signed Binary Proxy Execution|
Binaries signed with trusted digital certificates can execute on Windows systems protected by digital signature validation. Several Microsoft signed binaries that are default on Windows installations can be used to proxy execution of other files. This behavior may be abused by adversaries to execute malicious files that could bypass application whitelisting and signature validation on systems. This technique accounts for proxy execution methods that are not already accounted for within the existing techniques.
|T1216||Signed Script Proxy Execution|
Scripts signed with trusted certificates can be used to proxy execution of malicious files. This behavior may bypass signature validation restrictions and application whitelisting solutions that do not account for use of these scripts.
|T1198||SIP and Trust Provider Hijacking|
In user mode, Windows Authenticode digital signatures are used to verify a file's origin and integrity, variables that may be used to establish trust in signed code (ex: a driver with a valid Microsoft signature may be handled as safe). The signature validation process is handled via the WinVerifyTrust application programming interface (API) function, which accepts an inquiry and coordinates with the appropriate trust provider, which is responsible for validating parameters of a signature.
Software packing is a method of compressing or encrypting an executable. Packing an executable changes the file signature in an attempt to avoid signature-based detection. Most decompression techniques decompress the executable code in memory.
|T1151||Space after Filename|
Adversaries can hide a program's true filetype by changing the extension of a file. With certain file types (specifically this does not work with .app extensions), appending a space to the end of a filename will change how the file is processed by the operating system. For example, if there is a Mach-O executable file called evil.bin, when it is double clicked by a user, it will launch Terminal.app and execute. If this file is renamed to evil.txt, then when double clicked by a user, it will launch with the default text editing application (not executing the binary). However, if the file is renamed to "evil.txt " (note the space at the end), then when double clicked by a user, the true file type is determined by the OS and handled appropriately and the binary will be executed .
Microsoft’s Open Office XML (OOXML) specification defines an XML-based format for Office documents (.docx, xlsx, .pptx) to replace older binary formats (.doc, .xls, .ppt). OOXML files are packed together ZIP archives compromised of various XML files, referred to as parts, containing properties that collectively define how a document is rendered.
Timestomping is a technique that modifies the timestamps of a file (the modify, access, create, and change times), often to mimic files that are in the same folder. This is done, for example, on files that have been modified or created by the adversary so that they do not appear conspicuous to forensic investigators or file analysis tools. Timestomping may be used along with file name Masquerading to hide malware and tools.
|T1127||Trusted Developer Utilities|
There are many utilities used for software development related tasks that can be used to execute code in various forms to assist in development, debugging, and reverse engineering. These utilities may often be signed with legitimate certificates that allow them to execute on a system and proxy execution of malicious code through a trusted process that effectively bypasses application whitelisting defensive solutions.
Adversaries may steal the credentials of a specific user or service account using Credential Access techniques or capture credentials earlier in their reconnaissance process through social engineering for means of gaining Initial Access.
Adversaries may check for the presence of a virtual machine environment (VME) or sandbox to avoid potential detection of tools and activities. If the adversary detects a VME, they may alter their malware to conceal the core functions of the implant or disengage from the victim. They may also search for VME artifacts before dropping secondary or additional payloads.
Adversaries may use an existing, legitimate external Web service as a means for relaying commands to a compromised system.
|T1220||XSL Script Processing|
Extensible Stylesheet Language (XSL) files are commonly used to describe the processing and rendering of data within XML files. To support complex operations, the XSL standard includes support for embedded scripting in various languages.