Persistence

The adversary is trying to maintain their foothold.

Persistence consists of techniques that adversaries use to keep access to systems across restarts, changed credentials, and other interruptions that could cut off their access. Techniques used for persistence include any access, action, or configuration changes that let them maintain their foothold on systems, such as replacing or hijacking legitimate code or adding startup code.

ID: TA0003
Created: 17 October 2018
Last Modified: 19 July 2019

Techniques

Techniques: 18
ID Name Description
T1098 Account Manipulation Adversaries may manipulate accounts to maintain access to victim systems. Account manipulation may consist of any action that preserves adversary access to a compromised account, such as modifying credentials or permission groups. These actions could also include account activity designed to subvert security policies, such as performing iterative password updates to bypass password duration policies and preserve the life of compromised credentials. In order to create or manipulate accounts, the adversary must already have sufficient permissions on systems or the domain.
.001 Additional Azure Service Principal Credentials Adversaries may add adversary-controlled credentials for Azure Service Principals in addition to existing legitimate credentials to maintain persistent access to victim Azure accounts. Azure Service Principals support both password and certificate credentials. With sufficient permissions, there are a variety of ways to add credentials including the Azure Portal, Azure command line interface, and Azure or Az PowerShell modules.
.002 Exchange Email Delegate Permissions Adversaries may grant additional permission levels, such as ReadPermission or FullAccess, to maintain persistent access to an adversary-controlled email account. The Add-MailboxPermission PowerShell cmdlet, available in on-premises Exchange and in the cloud-based service Office 365, adds permissions to a mailbox.
.003 Add Office 365 Global Administrator Role An adversary may add the Global Administrator role to an adversary-controlled account to maintain persistent access to an Office 365 tenant. With sufficient permissions, a compromised account can gain almost unlimited access to data and settings (including the ability to reset the passwords of other admins) via the global admin role.
T1197 BITS Jobs Adversaries may abuse BITS jobs to persistently execute or clean up after malicious payloads. 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.
T1547 Boot or Logon Autostart Execution Adversaries may configure system settings to automatically execute a program during system boot or logon to maintain persistence or gain higher-level privileges on compromised systems. Operating systems may have mechanisms for automatically running a program on system boot or account logon.  These mechanisms may include automatically executing programs that are placed in specially designated directories or are referenced by repositories that store configuration information, such as the Windows Registry. An adversary may achieve the same goal by modifying or extending features of the kernel.
.001 Registry Run Keys / Startup Folder Adversaries may achieve persistence by adding a program to a startup folder or referencing it with a Registry run key. Adding an entry to the "run keys" in the Registry or startup folder will cause the program referenced to be executed when a user logs in. These programs will be executed under the context of the user and will have the account's associated permissions level.
.002 Authentication Package Adversaries may abuse authentication packages to execute DLLs when the system boots. Windows authentication package DLLs are loaded by the Local Security Authority (LSA) process at system start. They provide support for multiple logon processes and multiple security protocols to the operating system.
.003 Time Providers Adversaries may abuse time providers to execute DLLs when the system boots. The Windows Time service (W32Time) enables time synchronization across and within domains. W32Time time providers are responsible for retrieving time stamps from hardware/network resources and outputting these values to other network clients.
.004 Winlogon Helper DLL
.005 Security Support Provider Adversaries may abuse security support providers (SSPs) to execute DLLs when the system boots. Windows SSP DLLs are loaded into the Local Security Authority (LSA) process at system start. Once loaded into the LSA, SSP DLLs have access to encrypted and plaintext passwords that are stored in Windows, such as any logged-on user's Domain password or smart card PINs.
.006 Kernel Modules and Extensions Adversaries may modify the kernel to automatically execute programs on system boot. Loadable Kernel Modules (LKMs) are pieces of code that can be loaded and unloaded into the kernel upon demand. They extend the functionality of the kernel without the need to reboot the system. For example, one type of module is the device driver, which allows the kernel to access hardware connected to the system.  
.007 Re-opened Applications Adversaries may modify plist files to automatically run an application when a user logs in. Starting in Mac OS X 10.7 (Lion), users can specify certain applications to be re-opened when a user logs into their machine after reboot. While this is usually done via a Graphical User Interface (GUI) on an app-by-app basis, there are property list files (plist) that contain this information as well located at ~/Library/Preferences/com.apple.loginwindow.plist and ~/Library/Preferences/ByHost/com.apple.loginwindow.* .plist.
.008 LSASS Driver Adversaries may modify or add LSASS drivers to obtain persistence on compromised systems. The Windows security subsystem is a set of components that manage and enforce the security policy for a computer or domain. The Local Security Authority (LSA) is the main component responsible for local security policy and user authentication. The LSA includes multiple dynamic link libraries (DLLs) associated with various other security functions, all of which run in the context of the LSA Subsystem Service (LSASS) lsass.exe process.
.009 Shortcut Modification Adversaries may create or edit shortcuts to run a program during system boot or user login. Shortcuts or symbolic links are ways of referencing other files or programs that will be opened or executed when the shortcut is clicked or executed by a system startup process.
.010 Port Monitors Adversaries may use port monitors to run an attacker supplied DLL during system boot for persistence or privilege escalation. A port monitor can be set through the AddMonitor API call to set a DLL to be loaded at startup. This DLL can be located in C:\Windows\System32 and will be loaded by the print spooler service, spoolsv.exe, on boot. The spoolsv.exe process also runs under SYSTEM level permissions. Alternatively, an arbitrary DLL can be loaded if permissions allow writing a fully-qualified pathname for that DLL to HKLM\SYSTEM\CurrentControlSet\Control\Print\Monitors.
.011 Plist Modification Adversaries may modify plist files to run a program during system boot or user login. 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 /Library/Preferences (which execute with elevated privileges) and ~/Library/Preferences (which execute with a user's privileges).
T1037 Boot or Logon Initialization Scripts Adversaries may use scripts automatically executed at boot or logon initialization to establish persistence. Initialization scripts can be used to perform administrative functions, which may often execute other programs or send information to an internal logging server. These scripts can vary based on operating system and whether applied locally or remotely.
.001 Logon Script (Windows) Adversaries may use Windows logon scripts automatically executed at logon initialization to establish persistence. Windows allows logon scripts to be run whenever a specific user or group of users log into a system. This is done via adding a path to a script to the HKCU\Environment\UserInitMprLogonScript Registry key.
.002 Logon Script (Mac) Adversaries may use macOS logon scripts automatically executed at logon initialization to establish persistence. macOS allows logon scripts (known as login hooks) to be executed whenever a specific user logs into a system. A login hook tells Mac OS X to execute a certain script when a user logs in, but unlike Startup Items, a login hook executes as the elevated root user.
.003 Network Logon Script Adversaries may use network logon scripts automatically executed at logon initialization to establish persistence. Network logon scripts can be assigned using Active Directory or Group Policy Objects. These logon scripts run with the privileges of the user they are assigned to. Depending on the systems within the network, initializing one of these scripts could apply to more than one or potentially all systems.
.004 Rc.common Adversaries may use rc.common automatically executed at boot initialization to establish persistence. During the boot process, macOS executes source /etc/rc.common, which is a shell script containing various utility functions. This file also defines routines for processing command-line arguments and for gathering system settings and is thus recommended to include in the start of Startup Item Scripts . In macOS and OS X, this is now a deprecated mechanism in favor of Launch Agent and Launch Daemon but is currently still used.
.005 Startup Items Adversaries may use startup items automatically executed at boot initialization to establish persistence. Startup items execute during the final phase of the boot process and contain shell scripts or other executable files along with configuration information used by the system to determine the execution order for all startup items.
T1176 Browser Extensions Adversaries may abuse Internet browser extensions to establish persistence access to victim systems. Browser extensions or plugins are small programs that can add functionality and customize aspects of Internet browsers. They can be installed directly or through a browser's app store and generally have access and permissions to everything that the browser can access.
T1554 Compromise Client Software Binary Adversaries may modify client software binaries to establish persistent access to systems. Client software enables users to access services provided by a server. Common client software types are SSH clients, FTP clients, email clients, and web browsers.
T1136 Create Account Adversaries may create an account to maintain access to victim systems. With a sufficient level of access, creating such accounts may be used to establish secondary credentialed access that do not require persistent remote access tools to be deployed on the system.
.001 Local Account Adversaries may create a local account to maintain access to victim systems. Local accounts are those configured by an organization for use by users, remote support, services, or for administration on a single system or service. With a sufficient level of access, the net user /add command can be used to create a local account.
.002 Domain Account Adversaries may create a domain account to maintain access to victim systems. Domain accounts are those managed by Active Directory Domain Services where access and permissions are configured across systems and services that are part of that domain. Domain accounts can cover user, administrator, and service accounts. With a sufficient level of access, the net user /add /domain command can be used to create a domain account.
.003 Cloud Account Adversaries may create a cloud account to maintain access to victim systems. With a sufficient level of access, such accounts may be used to establish secondary credentialed access that does not require persistent remote access tools to be deployed on the system.
T1543 Create or Modify System Process Adversaries may create or modify system-level processes to repeatedly execute malicious payloads as part of persistence. When operating systems boot up, they can start processes that perform background system functions. On Windows and Linux, these system processes are referred to as services. On macOS, launchd processes known as Launch Daemon and Launch Agent are run to finish system initialization and load user specific parameters.
.001 Launch Agent Adversaries may create or modify launch agents to repeatedly execute malicious payloads as part of persistence. Per Apple’s developer documentation, when a user logs in, a per-user launchd process is started which loads the parameters for each launch-on-demand user agent from the property list (plist) files found in /System/Library/LaunchAgents, /Library/LaunchAgents, and $HOME/Library/LaunchAgents . These launch agents have property list files which point to the executables that will be launched .
.002 Systemd Service Adversaries may create or modify systemd services to repeatedly execute malicious payloads as part of persistence. The systemd service manager is commonly used for managing background daemon processes (also known as services) and other system resources. Systemd is the default initialization (init) system on many Linux distributions starting with Debian 8, Ubuntu 15.04, CentOS 7, RHEL 7, Fedora 15, and replaces legacy init systems including SysVinit and Upstart while remaining backwards compatible with the aforementioned init systems.
.003 Windows Service Adversaries may create or modify Windows services to repeatedly execute malicious payloads as part of persistence. When Windows boots up, it starts programs or applications called services that perform background system functions. Windows service configuration information, including the file path to the service's executable or recovery programs/commands, is stored in the Windows Registry. Service configurations can be modified using utilities such as sc.exe and Reg.
.004 Launch Daemon Adversaries may create or modify launch daemons to repeatedly execute malicious payloads as part of persistence. Per Apple’s developer documentation, when macOS and OS X boot up, launchd is run to finish system initialization. This process loads the parameters for each launch-on-demand system-level daemon from the property list (plist) files found in /System/Library/LaunchDaemons and /Library/LaunchDaemons . These LaunchDaemons have property list files which point to the executables that will be launched .
T1546 Event Triggered Execution Adversaries may establish persistence and/or elevate privileges using system mechanisms that trigger execution based on specific events. Various operating systems have means to monitor and subscribe to events such as logons or other user activity such as running specific applications/binaries.
.001 Change Default File Association Adversaries may establish persistence by executing malicious content triggered by a file type association. When a file is opened, the default program used to open the file (also called the file association or handler) is checked. File association selections are stored in the Windows Registry and can be edited by users, administrators, or programs that have Registry access or by administrators using the built-in assoc utility. Applications can modify the file association for a given file extension to call an arbitrary program when a file with the given extension is opened.
.002 Screensaver Adversaries may establish persistence by executing malicious content triggered by user inactivity. Screensavers are programs that execute after a configurable time of user inactivity and consist of Portable Executable (PE) files with a .scr file extension. The Windows screensaver application scrnsave.scr is located in C:\Windows\System32\, and C:\Windows\sysWOW64\ on 64-bit Windows systems, along with screensavers included with base Windows installations.
.003 Windows Management Instrumentation Event Subscription Adversaries may establish persistence and elevate privileges by executing malicious content triggered by a Windows Management Instrumentation (WMI) event subscription. WMI can be used to install event filters, providers, consumers, and bindings that execute code when a defined event occurs. Examples of events that may be subscribed to are the wall clock time, user loging, or the computer's uptime.
.004 .bash_profile and .bashrc Adversaries may establish persistence by executing malicious content triggered by a user’s shell. ~/.bash_profile and ~/.bashrc are shell scripts that contain shell commands. These files are executed in a user's context when a new shell opens or when a user logs in so that their environment is set correctly.
.005 Trap Adversaries may establish persistence by executing malicious content triggered by an interrupt signal. The trap command allows programs and shells to specify commands that will be executed upon receiving interrupt signals. A common situation is a script allowing for graceful termination and handling of common keyboard interrupts like ctrl+c and ctrl+d.
.006 LC_LOAD_DYLIB Addition Adversaries may establish persistence by executing malicious content triggered by the execution of tainted binaries. Mach-O binaries have a series of headers that are used to perform certain operations when a binary is loaded. The LC_LOAD_DYLIB header in a Mach-O binary tells macOS and OS X which dynamic libraries (dylibs) to load during execution time. These can be added ad-hoc to the compiled binary as long as adjustments are made to the rest of the fields and dependencies. There are tools available to perform these changes.
.007 Netsh Helper DLL Adversaries may establish persistence by executing malicious content triggered by Netsh Helper DLLs. Netsh.exe (also referred to as Netshell) is a command-line scripting utility used to interact with the network configuration of a system. It contains functionality to add helper DLLs for extending functionality of the utility. The paths to registered netsh.exe helper DLLs are entered into the Windows Registry at HKLM\SOFTWARE\Microsoft\Netsh.
.008 Accessibility Features Adversaries may establish persistence and/or elevate privileges by executing malicious content triggered by accessibility features. Windows contains accessibility features that may be launched with a key combination before a user has logged in (ex: when the user is on the Windows logon screen). An adversary can modify the way these programs are launched to get a command prompt or backdoor without logging in to the system.
.009 AppCert DLLs Adversaries may establish persistence and/or elevate privileges by executing malicious content triggered by AppCert DLLs loaded into processes. Dynamic-link libraries (DLLs) that are specified in the AppCertDLLs Registry key under HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Session Manager\ are loaded into every process that calls the ubiquitously used application programming interface (API) functions CreateProcess, CreateProcessAsUser, CreateProcessWithLoginW, CreateProcessWithTokenW, or WinExec.
.010 AppInit DLLs Adversaries may establish persistence and/or elevate privileges by executing malicious content triggered by AppInit DLLs loaded into processes. Dynamic-link libraries (DLLs) that are specified in the AppInit_DLLs value in the Registry keys HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\Windows or HKEY_LOCAL_MACHINE\Software\Wow6432Node\Microsoft\Windows NT\CurrentVersion\Windows are loaded by user32.dll into every process that loads user32.dll. In practice this is nearly every program, since user32.dll is a very common library.
.011 Application Shimming Adversaries may establish persistence and/or elevate privileges by executing malicious content triggered by application shims. The Microsoft Windows Application Compatibility Infrastructure/Framework (Application Shim) was created to allow for backward compatibility of software as the operating system codebase changes over time. For example, the application shimming feature allows developers to apply fixes to applications (without rewriting code) that were created for Windows XP so that it will work with Windows 10.
.012 Image File Execution Options Injection Adversaries may establish persistence and/or elevate privileges by executing malicious content triggered by Image File Execution Options (IEFO) debuggers. IEFOs 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).
.013 PowerShell Profile Adversaries may gain persistence and elevate privileges by executing malicious content triggered by PowerShell profiles. A PowerShell profile (profile.ps1) is a script that runs when PowerShell starts and can be used as a logon script to customize user environments.
.014 Emond Adversaries may gain persistence and elevate privileges by executing malicious content triggered by the Event Monitor Daemon (emond). Emond is a Launch Daemon that accepts events from various services, runs them through a simple rules engine, and takes action. The emond binary at /sbin/emond will load any rules from the /etc/emond.d/rules/ directory and take action once an explicitly defined event takes place.
.015 Component Object Model Hijacking Adversaries may establish persistence by executing malicious content triggered by hijacked references to Component Object Model (COM) objects. COM is a system within Windows to enable interaction between software components through the operating system. References to various COM objects are stored in the Registry.
T1133 External Remote Services Adversaries may leverage external-facing remote services to initially access and/or persist within a network. Remote services such as VPNs, Citrix, and other access mechanisms allow users to connect to internal enterprise network resources from external locations. There are often remote service gateways that manage connections and credential authentication for these services. Services such as Windows Remote Management can also be used externally.
T1574 Hijack Execution Flow Adversaries may execute their own malicious payloads by hijacking the way operating systems run programs. Hijacking execution flow can be for the purposes of persistence, since this hijacked execution may reoccur over time. Adversaries may also use these mechanisms to elevate privileges or evade defenses, such as whitelisting or other restrictions on execution.
.001 DLL Search Order Hijacking Adversaries may execute their own malicious payloads by hijacking the search order used to load DLLs. Windows systems use a common method to look for required DLLs to load into a program. Hijacking DLL loads may be for the purpose of establishing persistence as well as elevating privileges and/or evading restrictions on file execution.
.002 DLL Side-Loading Adversaries may execute their own malicious payloads by hijacking the library manifest used to load DLLs. Adversaries may take advantage of vague references in the library manifest of a program by replacing a legitimate library with a malicious one, causing the operating system to load their malicious library when it is called for by the victim program.
.004 Dylib Hijacking Adversaries may execute their own malicious payloads by hijacking ambiguous paths used to load libraries. Adversaries may plant trojan dynamic libraries, in a directory that will be searched by the operating system before the legitimate library specified by the victim program, so that their malicious library will be loaded into the victim program instead. MacOS and OS X use a common method to look for required dynamic libraries (dylib) to load into a program based on search paths.
.005 Executable Installer File Permissions Weakness Adversaries may execute their own malicious payloads by hijacking the binaries used by an installer. These processes may automatically execute specific binaries as part of their functionality or to perform other actions. If the permissions on the file system directory containing a target binary, or permissions on the binary itself, are improperly set, then the target binary may be overwritten with another binary using user-level permissions and executed by the original process. If the original process and thread are running under a higher permissions level, then the replaced binary will also execute under higher-level permissions, which could include SYSTEM.
.006 LD_PRELOAD Adversaries may execute their own malicious payloads by hijacking environment variables used to load libraries. Adversaries may set the LD_PRELOAD environment variable to point at malicious libraries that match the name of legitimate libraries which are requested by a victim program, causing the operating system to load the adversary's malicious code upon execution of the victim program. This environment variable is used to control when different shared libraries are loaded by a program. Libraries specified by this variable with be loaded and mapped into memory by dlopen() and mmap() respectively.
.007 Path Interception by PATH Environment Variable Adversaries may execute their own malicious payloads by hijacking environment variables used to load libraries. Adversaries may place a program in an earlier entry in the list of directories stored in the PATH environment variable, which Windows will then execute when it searches sequentially through that PATH listing in search of the binary that was called from a script or the command line.
.008 Path Interception by Search Order Hijacking Adversaries may execute their own malicious payloads by hijacking the search order used to load other programs. Because some programs do not call other programs using the full path, adversaries may place their own file in the directory where the calling program is located, causing the operating system to launch their malicious software at the request of the calling program.
.009 Path Interception by Unquoted Path Adversaries may execute their own malicious payloads by hijacking vulnerable file path references. Adversaries can take advantage of paths that lack surrounding quotations by placing an executable in a higher level directory within the path, so that Windows will choose the adversary's executable to launch.
.010 Services File Permissions Weakness Adversaries may execute their own malicious payloads by hijacking the binaries used by services. Adversaries may use flaws in the permissions of Windows services to replace the binary that is executed upon service start. These service processes may automatically execute specific binaries as part of their functionality or to perform other actions. If the permissions on the file system directory containing a target binary, or permissions on the binary itself are improperly set, then the target binary may be overwritten with another binary using user-level permissions and executed by the original process. If the original process and thread are running under a higher permissions level, then the replaced binary will also execute under higher-level permissions, which could include SYSTEM.
.011 Services Registry Permissions Weakness Adversaries may execute their own malicious payloads by hijacking the Registry entries used by services. Adversaries may use flaws in the permissions for registry to redirect from the originally specified executable to one that they control, in order to launch their own code at Service start. Windows stores local service configuration information in the Registry under HKLM\SYSTEM\CurrentControlSet\Services. The information stored under a service's Registry keys can be manipulated to modify a service's execution parameters through tools such as the service controller, sc.exe, PowerShell, or Reg. Access to Registry keys is controlled through Access Control Lists and permissions.
T1525 Implant Container Image Adversaries may implant cloud container images with malicious code to establish persistence. Amazon Web Service (AWS) Amazon Machine Images (AMI), Google Cloud Platform (GCP) Images, and Azure Images as well as popular container runtimes such as Docker can be implanted or backdoored. Depending on how the infrastructure is provisioned, this could provide persistent access if the infrastructure provisioning tool is instructed to always use the latest image.
T1137 Office Application Startup Adversaries may leverage Microsoft Office-based applications for persistence between startups. Microsoft Office is a fairly common application suite on Windows-based operating systems within an enterprise network. There are multiple mechanisms that can be used with Office for persistence when an Office-based application is started; this can include the use of Office Template Macros and add-ins.
.001 Office Template Macros Adversaries may abuse Microsoft Office templates to obtain persistence on a compromised system. Microsoft Office contains templates that are part of common Office applications and are used to customize styles. The base templates within the application are used each time an application starts.
.002 Office Test Adversaries may abuse the Microsoft Office "Office Test" Registry key to obtain persistence on a compromised system. An Office Test Registry location exists that allows a user to specify an arbitrary DLL that will be executed every time an Office application is started. This Registry key is thought to be used by Microsoft to load DLLs for testing and debugging purposes while developing Office applications. This Registry key is not created by default during an Office installation.
.003 Outlook Forms Adversaries may abuse Microsoft Outlook forms to obtain persistence on a compromised system. Outlook forms are used as templates for presentation and functionality in Outlook messages. Custom Outlook forms can be created that will execute code when a specifically crafted email is sent by an adversary utilizing the same custom Outlook form.
.004 Outlook Home Page Adversaries may abuse Microsoft Outlook's Home Page feature to obtain persistence on a compromised system. Outlook Home Page is a legacy feature used to customize the presentation of Outlook folders. This feature allows for an internal or external URL to be loaded and presented whenever a folder is opened. A malicious HTML page can be crafted that will execute code when loaded by Outlook Home Page.
.005 Outlook Rules Adversaries may abuse Microsoft Outlook rules to obtain persistence on a compromised system. Outlook rules allow a user to define automated behavior to manage email messages. A benign rule might, for example, automatically move an email to a particular folder in Outlook if it contains specific words from a specific sender. Malicious Outlook rules can be created that can trigger code execution when an adversary sends a specifically crafted email to that user.
.006 Add-ins Adversaries may abuse Microsoft Office add-ins to obtain persistence on a compromised system. Office add-ins can be used to add functionality to Office programs. There are different types of add-ins that can be used by the various Office products; including Word/Excel add-in Libraries (WLL/XLL), VBA add-ins, Office Component Object Model (COM) add-ins, automation add-ins, VBA Editor (VBE), Visual Studio Tools for Office (VSTO) add-ins, and Outlook add-ins.
T1542 Pre-OS Boot Adversaries may abuse Pre-OS Boot mechanisms as a way to establish persistence on a system. During the booting process of a computer, firmware and various startup services are loaded before the operating system. These programs control flow of execution before the operating system takes control.
.001 System Firmware Adversaries may modify system firmware to persist on systems.The BIOS (Basic Input/Output System) and The Unified Extensible Firmware Interface (UEFI) or Extensible Firmware Interface (EFI) are examples of system firmware that operate as the software interface between the operating system and hardware of a computer.
.002 Component Firmware Adversaries may modify component firmware to persist on systems. 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/devices that may not have the same capability or level of integrity checking.
.003 Bootkit Adversaries may use bootkits to persist on systems. Bootkits reside at a layer below the operating system and may make it difficult to perform full remediation unless an organization suspects one was used and can act accordingly.
T1053 Scheduled Task/Job Adversaries may abuse task scheduling functionality to facilitate initial or recurring execution of malicious code. Utilities exist within all major operating systems to schedule programs or scripts to be executed at a specified date and time. A task can also be scheduled on a remote system, provided the proper authentication is met (ex: RPC and file and printer sharing in Windows environments). Scheduling a task on a remote system typically requires being a member of an admin or otherwise privileged group on the remote system.
.001 At (Linux) Adversaries may abuse the at utility to perform task scheduling for initial or recurring execution of malicious code. The at command within Linux operating systems enables administrators to schedule tasks.
.002 At (Windows) Adversaries may abuse the at.exe utility to perform task scheduling for initial or recurring execution of malicious code. The at utility exists as an executable within Windows for scheduling tasks at a specified time and date. Using at requires that the Task Scheduler service be running, and the user to be logged on as a member of the local Administrators group.
.003 Cron Adversaries may abuse the cron utility to perform task scheduling for initial or recurring execution of malicious code. The cron utility is a time-based job scheduler for Unix-like operating systems. The crontab file contains the schedule of cron entries to be run and the specified times for execution. Any crontab files are stored in operating system-specific file paths.
.004 Launchd Adversaries may abuse the Launchd daemon to perform task scheduling for initial or recurring execution of malicious code. The launchd daemon, native to macOS, is responsible for loading and maintaining services within the operating system. This process loads the parameters for each launch-on-demand system-level daemon from the property list (plist) files found in /System/Library/LaunchDaemons and /Library/LaunchDaemons . These LaunchDaemons have property list files which point to the executables that will be launched .
.005 Scheduled Task Adversaries may abuse the Windows Task Scheduler to perform task scheduling for initial or recurring execution of malicious code. There are multiple ways to access the Task Scheduler in Windows. The schtasks can be run directly on the command line, or the Task Scheduler can be opened through the GUI within the Administrator Tools section of the Control Panel. In some cases, adversaries have used a .NET wrapper for the Windows Task Scheduler, and alternatively, adversaries have used the Windows netapi32 library to create a scheduled task.
T1505 Server Software Component Adversaries may abuse legitimate extensible development features of servers to establish persistent access to systems. Enterprise server applications may include features that allow developers to write and install software or scripts to extend the functionality of the main application. Adversaries may install malicious components to extend and abuse server applications.
.001 SQL Stored Procedures Adversaries may abuse SQL stored procedures to establish persistent access to systems. SQL Stored Procedures are code that can be saved and reused so that database users do not waste time rewriting frequently used SQL queries. Stored procedures can be invoked via SQL statements to the database using the procedure name or via defined events (e.g. when a SQL server application is started/restarted).
.002 Transport Agent Adversaries may abuse Microsoft transport agents to establish persistent access to systems. Microsoft Exchange transport agents can operate on email messages passing through the transport pipeline to perform various tasks such as filtering spam, filtering malicious attachments, journaling, or adding a corporate signature to the end of all outgoing emails. Transport agents can be written by application developers and then compiled to .NET assemblies that are subsequently registered with the Exchange server. Transport agents will be invoked during a specified stage of email processing and carry out developer defined tasks.
.003 Web Shell Adversaries may backdoor web servers with web shells to establish persistent access to systems. A Web shell is a Web script that is placed on an openly accessible Web server to allow an adversary to use the Web server as a gateway into a network. A Web shell may provide a set of functions to execute or a command-line interface on the system that hosts the Web server.
T1545 Traffic Signaling Adversaries may use traffic signaling to hide open ports used for persistence or command and control. Traffic signaling is a well-established method used by both defenders and adversaries to hide open ports from access/discovery. 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 (i.e. Port Knocking), 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.
.001 Port Knocking Adversaries may use port knocking to hide open ports used for persistence or command and control. To enable a port, an adversary sends a series of attempted connections to a predefined sequence of closed ports. After the sequence is completed, opening a port is often accomplished by the host based firewall, but could also be implemented by custom software.
T1078 Valid Accounts Adversaries may obtain and abuse credentials of existing accounts as a means of gaining Initial Access, Persistence, Privilege Escalation, or Defense Evasion. Compromised credentials may be used to bypass access controls placed on various resources on systems within the network and may even be used for persistent access to remote systems and externally available services, such as VPNs, Outlook Web Access and remote desktop. Compromised credentials may also grant an adversary increased privilege to specific systems or access to restricted areas of the network. Adversaries may choose not to use malware or tools in conjunction with the legitimate access those credentials provide to make it harder to detect their presence.
.001 Default Accounts Adversaries may obtain and abuse credentials of a default account as a means of gaining Initial Access, Persistence, Privilege Escalation, or Defense Evasion. Default accounts are those that are built-into an OS, such as the Guest or Administrator accounts on Windows systems or default factory/provider set accounts on other types of systems, software, or devices.
.002 Domain Accounts Adversaries may obtain and abuse credentials of a domain account as a means of gaining Initial Access, Persistence, Privilege Escalation, or Defense Evasion. Domain accounts are those managed by Active Directory Domain Services where access and permissions are configured across systems and services that are part of that domain. Domain accounts can cover users, administrators, and services.
.003 Local Accounts Adversaries may obtain and abuse credentials of a local account as a means of gaining Initial Access, Persistence, Privilege Escalation, or Defense Evasion. Local accounts are those configured by an organization for use by users, remote support, services, or for administration on a single system or service.
.004 Cloud Accounts Adversaries may obtain and abuse credentials of a cloud account as a means of gaining Initial Access, Persistence, Privilege Escalation, or Defense Evasion. Cloud accounts are those created and configured by an organization for use by users, remote support, services, or for administration of resources within a cloud service provider or SaaS application. In some cases, cloud accounts may be federated with traditional identity management system, such as Window Active Directory.