T1543.001 - Create or Modify System Process: Launch Agent

Description from ATT&CK (opens in a new tab)

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.(Citation: AppleDocs Launch Agent Daemons)(Citation: OSX Keydnap malware) (Citation: Antiquated Mac Malware) Property list files use the Label, ProgramArguments , and RunAtLoad keys to identify the Launch Agent's name, executable location, and execution time.(Citation: OSX.Dok Malware) 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 (opens in a new tab) 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.(Citation: Sofacy Komplex Trojan)(Citation: Methods of Mac Malware Persistence) 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.(Citation: OSX Malware Detection)(Citation: OceanLotus for OS X)

Atomic Tests

• Atomic Test #1 - Launch Agent

• Atomic Test #2 - Event Monitor Daemon Persistence

• Atomic Test #3 - Launch Agent - Root Directory

Atomic Test #1 - Launch Agent

Create a plist and execute it

Supported Platforms: macOS

auto_generated_guid: a5983dee-bf6c-4eaf-951c-dbc1a7b90900

Inputs:

Attack Commands: Run with bash! Elevation Required (e.g. root or admin)

if [ ! -d ~/Library/LaunchAgents ]; then mkdir ~/Library/LaunchAgents; fi;
sudo cp #{path_malicious_plist} ~/Library/LaunchAgents/#{plist_filename}
sudo launchctl load -w ~/Library/LaunchAgents/#{plist_filename}

Cleanup Commands:

sudo launchctl unload ~/Library/LaunchAgents/#{plist_filename}
sudo rm ~/Library/LaunchAgents/#{plist_filename}

Dependencies: Run with bash!

Description: The shared library must exist on disk at specified location (#{path_malicious_plist})

Check Prereq Commands:

if [ -f #{path_malicious_plist} ]; then exit 0; else exit 1; fi;

Get Prereq Commands:

echo "The shared library doesn't exist. Check the path"; exit 1;

Atomic Test #2 - Event Monitor Daemon Persistence

This test adds persistence via a plist to execute via the macOS Event Monitor Daemon.

Supported Platforms: macOS

auto_generated_guid: 11979f23-9b9d-482a-9935-6fc9cd022c3e

Inputs:

Attack Commands: Run with bash! Elevation Required (e.g. root or admin)

sudo cp #{script_location} #{script_destination}
sudo touch /private/var/db/emondClients/#{empty_file}

Cleanup Commands:

sudo rm #{script_destination}
sudo rm /private/var/db/emondClients/#{empty_file}

Atomic Test #3 - Launch Agent - Root Directory

Create a plist and execute it

Supported Platforms: macOS

auto_generated_guid: 66774fa8-c562-4bae-a58d-5264a0dd9dd7

Inputs:

Attack Commands: Run with bash! Elevation Required (e.g. root or admin)

sudo cp #{path_malicious_plist} /Library/LaunchAgents/#{plist_filename}
launchctl load -w /Library/LaunchAgents/#{plist_filename}

Cleanup Commands:

launchctl unload /Library/LaunchAgents/#{plist_filename}
sudo rm /Library/LaunchAgents/#{plist_filename}
sudo rm /tmp/T1543_001_atomicredteam.txt

Dependencies: Run with bash!

Description: /Library/LaunchAgents must exist

Check Prereq Commands:

if [ ! -d /Library/LaunchAgents ]; then mkdir /Library/LaunchAgents; exit 0; fi;

Get Prereq Commands:

echo "Failed to create /Library/LaunchAgents"; exit 1;

Description: The shared library must exist on disk at specified location (#{path_malicious_plist})

Check Prereq Commands:

if [ -f #{path_malicious_plist} ]; then exit 0; else exit 1; fi;

Get Prereq Commands:

echo "The plist file doesn't exist. Check the path and try again."; exit 1;