Boot or Logon Initialization Scripts: Login Hook

Adversaries may use a Login Hook to establish persistence executed upon user logon. A login hook is a plist file that points to a specific script to execute with root privileges upon user logon. The plist file is located in the /Library/Preferences/ file and can be modified using the defaults command-line utility. This behavior is the same for logout hooks where a script can be executed upon user logout. All hooks require administrator permissions to modify or create hooks.[1][2]

Adversaries can add or insert a path to a malicious script in the file, using the LoginHook or LogoutHook key-value pair. The malicious script is executed upon the next user login. If a login hook already exists, adversaries can add additional commands to an existing login hook. There can be only one login and logout hook on a system at a time.[3][4]

Note: Login hooks were deprecated in 10.11 version of macOS in favor of Launch Daemon and Launch Agent

ID: T1037.002
Sub-technique of:  T1037
Platforms: macOS
Version: 2.0
Created: 10 January 2020
Last Modified: 20 April 2022


ID Mitigation Description
M1022 Restrict File and Directory Permissions

Restrict write access to logon scripts to specific administrators.


ID Data Source Data Component
DS0017 Command Command Execution
DS0022 File File Creation
File Modification
DS0009 Process Process Creation

Monitor logon scripts for unusual access by abnormal users or at abnormal times. Look for files added or modified by unusual accounts outside of normal administration duties. Monitor running process for actions that could be indicative of abnormal programs or executables running upon logon.