Create or Modify System Process: Launch Agent

Adversaries may create or modify launch agents to repeatedly execute malicious payloads as part of persistence. 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) file found in /System/Library/LaunchAgents, /Library/LaunchAgents, and ~/Library/LaunchAgents.[1][2] [3] Property list files use the Label, ProgramArguments , and RunAtLoad keys to identify the Launch Agent's name, executable location, and execution time.[4] Launch Agents are often installed to perform updates to programs, launch user specified programs at login, or to conduct other developer tasks.

Launch Agents can also be executed using the Launchctl command.

Adversaries may install a new Launch Agent that executes at login by placing a .plist file into the appropriate folders with the RunAtLoad or KeepAlive keys set to true.[5][6] The Launch Agent name may be disguised by using a name from the related operating system or benign software. Launch Agents are created with user level privileges and execute with user level permissions.[7][8]

ID: T1543.001
Sub-technique of:  T1543
Platforms: macOS
Permissions Required: Administrator, User
Contributors: Antonio Piazza, @antman1p
Version: 1.4
Created: 17 January 2020
Last Modified: 21 April 2022

Procedure Examples

ID Name Description
S0482 Bundlore

Bundlore can persist via a LaunchAgent.[9]

S0274 Calisto

Calisto adds a .plist file to the /Library/LaunchAgents folder to maintain persistence.[10]

S0369 CoinTicker

CoinTicker creates user launch agents named .espl.plist and com.apple.[random string].plist to establish persistence.[11]

S0492 CookieMiner

CookieMiner has installed multiple new Launch Agents in order to maintain persistence for cryptocurrency mining software.[12]

S0235 CrossRAT

CrossRAT creates a Launch Agent on macOS.[13]

S0497 Dacls

Dacls can establish persistence via a LaunchAgent.[14][15]

S0281 Dok

Dok installs two LaunchAgents to redirect all network traffic with a randomly generated name for each plist file maintaining the format com.random.name.plist.[16][17]

S0277 FruitFly

FruitFly persists via a Launch Agent.[16]

S0690 Green Lambert

Green Lambert can create a Launch Agent with the RunAtLoad key-value pair set to true, ensuring the com.apple.GrowlHelper.plist file runs every time a user logs in.[18][19]

S0276 Keydnap

Keydnap uses a Launch Agent to persist.[20]

S0162 Komplex

The Komplex trojan creates a persistent launch agent called with $HOME/Library/LaunchAgents/com.apple.updates.plist with launchctl load -w ~/Library/LaunchAgents/com.apple.updates.plist.[5]

S1016 MacMa

MacMa installs a com.apple.softwareupdate.plist file in the /LaunchAgents folder with the RunAtLoad value set to true. Upon user login, MacMa is executed from /var/root/.local/softwareupdate with root privileges. Some variations also include the LimitLoadToSessionType key with the value Aqua, ensuring the MacMa only runs when there is a logged in GUI user.[21][22]

S1048 macOS.OSAMiner

macOS.OSAMiner has placed a Stripped Payloads with a plist extension in the Launch Agent's folder. [23]

S0282 MacSpy

MacSpy persists via a Launch Agent.[16]

S0198 NETWIRE

NETWIRE can use launch agents for persistence.[24]

S0352 OSX_OCEANLOTUS.D

OSX_OCEANLOTUS.D can create a persistence file in the folder /Library/LaunchAgents.[25][26]

S0279 Proton

Proton persists via Launch Agent.[16]

S0595 ThiefQuest

ThiefQuest installs a launch item using an embedded encrypted launch agent property list template. The plist file is installed in the ~/Library/LaunchAgents/ folder and configured with the path to the persistent binary located in the ~/Library/ folder.[27]

Mitigations

ID Mitigation Description
M1022 Restrict File and Directory Permissions

Set group policies to restrict file permissions to the ~/launchagents folder.[28]

Detection

ID Data Source Data Component Detects
DS0017 Command Command Execution

Ensure Launch Agent's ProgramArguments key pointing to executables located in the /tmp or /shared folders are in alignment with enterprise policy. Ensure all Launch Agents with the RunAtLoad key set to true are in alignment with policy.

DS0022 File File Creation

Monitor for newly constructed files that may create or modify launch agents to repeatedly execute malicious payloads as part of persistence.

File Modification

Launch Agents also require files on disk for persistence which can also be monitored via other file monitoring applications.

DS0019 Service Service Creation

Monitor Launch Agent creation through additional plist files and utilities such as Objective-See’s KnockKnock application.

Service Modification

Monitor for changes made to launch agents to repeatedly execute malicious payloads as part of persistence.

References

  1. Apple. (n.d.). Creating Launch Daemons and Agents. Retrieved July 10, 2017.
  2. Marc-Etienne M.Leveille. (2016, July 6). New OSX/Keydnap malware is hungry for credentials. Retrieved July 3, 2017.
  3. Thomas Reed. (2017, January 18). New Mac backdoor using antiquated code. Retrieved July 5, 2017.
  4. Thomas Reed. (2017, July 7). New OSX.Dok malware intercepts web traffic. Retrieved July 10, 2017.
  5. Dani Creus, Tyler Halfpop, Robert Falcone. (2016, September 26). Sofacy's 'Komplex' OS X Trojan. Retrieved July 8, 2017.
  6. Patrick Wardle. (2014, September). Methods of Malware Persistence on Mac OS X. Retrieved July 5, 2017.
  7. Patrick Wardle. (2016, February 29). Let's Play Doctor: Practical OS X Malware Detection & Analysis. Retrieved July 10, 2017.
  8. Eddie Lee. (2016, February 17). OceanLotus for OS X - an Application Bundle Pretending to be an Adobe Flash Update. Retrieved July 5, 2017.
  9. Sushko, O. (2019, April 17). macOS Bundlore: Mac Virus Bypassing macOS Security Features. Retrieved June 30, 2020.
  10. Kuzin, M., Zelensky S. (2018, July 20). Calisto Trojan for macOS. Retrieved September 7, 2018.
  11. Thomas Reed. (2018, October 29). Mac cryptocurrency ticker app installs backdoors. Retrieved April 23, 2019.
  12. Chen, y., et al. (2019, January 31). Mac Malware Steals Cryptocurrency Exchanges’ Cookies. Retrieved July 22, 2020.
  13. Blaich, A., et al. (2018, January 18). Dark Caracal: Cyber-espionage at a Global Scale. Retrieved April 11, 2018.
  14. Stokes, P. (2020, July 27). Four Distinct Families of Lazarus Malware Target Apple’s macOS Platform. Retrieved August 7, 2020.