cyberstrikeus T1037.002 Login Hook
Sub-technique of: T1037
High-Level Description
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/com.apple.loginwindow.plist 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.
Adversaries can add or insert a path to a malicious script in the com.apple.loginwindow.plist 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.
Note: Login hooks were deprecated in 10.11 version of macOS in favor of Launch Daemon and Launch Agent
Kill Chain Phase
- Persistence (TA0003)
- Privilege Escalation (TA0004)
Platforms: macOS
What to Check
- Identify if Login Hook technique is applicable to target environment
- Check macOS systems for indicators of Login Hook
- Verify mitigations are bypassed or absent (1 known mitigations)
- Assess detection coverage (1 detection strategies)
How to Test
Atomic Red Team Tests
The following tests are from Atomic Red Team and provide actionable ways to test this technique:
Atomic Test 1: Logon Scripts - Mac
Mac logon script
Supported Platforms: macos
Manual Testing
If Atomic Red Team tests are not applicable, manually verify the technique by:
Identify Attack Surface: Determine if the target environment is susceptible to Login Hook by examining the target platforms (macOS).
Assess Existing Defenses: Review whether mitigations for T1037.002 are in place. If defenses are absent or misconfigured, this technique may be exploitable.
Execute Test: Use tools and methods described in the MITRE ATT&CK page and external references below.
Remediation Guide
M1022 Restrict File and Directory Permissions
Restrict write access to logon scripts to specific administrators.
Detection
Detection Strategy for Login Hook Persistence on macOS
Risk Assessment
| Finding | Severity | Impact |
|---|---|---|
| Login Hook technique applicable | High | Persistence |
CWE Categories
| CWE ID | Title |
|---|---|
| CWE-276 | Incorrect Default Permissions |