sigmamediumHunting

WDAC Policy File Creation In CodeIntegrity Folder

Attackers can craft a custom Windows Defender Application Control (WDAC) policy that blocks Endpoint Detection and Response (EDR) components while allowing their own malicious code. The policy is placed in the privileged Windows Code Integrity folder (C:\Windows\System32\CodeIntegrity\). Upon reboot, the policy prevents EDR drivers from loading, effectively bypassing security measures and may further enable undetected lateral movement within an Active Directory environment.

MITRE ATT&CK

T1685

Detection Query

selection:
  TargetFilename|contains: :\Windows\System32\CodeIntegrity\
  TargetFilename|endswith:
    - .cip
    - .p7b
  IntegrityLevel: High
condition: selection

Author

Andreas Braathen (mnemonic.io)

Created

2025-01-30

Data Sources

windowsFile Events

Platforms

windows

References

Tags

attack.defense-impairmentattack.t1685detection.threat-hunting

Raw Content

title: WDAC Policy File Creation In CodeIntegrity Folder
id: 121b25f7-b9d6-4b37-afa0-cba317ec52f3
status: experimental
description: |
    Attackers can craft a custom Windows Defender Application Control (WDAC) policy that blocks Endpoint Detection and Response (EDR) components while allowing their own malicious code. The policy is placed in the privileged Windows Code Integrity folder (C:\Windows\System32\CodeIntegrity\). Upon reboot, the policy prevents EDR drivers from loading, effectively bypassing security measures and may further enable undetected lateral movement within an Active Directory environment.
references:
    - https://beierle.win/2024-12-20-Weaponizing-WDAC-Killing-the-Dreams-of-EDR/
    - https://www.virustotal.com/gui/file/d2a4f52a9923336f119a52e531bbb1e66f18322fd8efa9af1a64b94f4d36dc97
author: Andreas Braathen (mnemonic.io)
date: 2025-01-30
tags:
    - attack.defense-impairment
    - attack.t1685
    - detection.threat-hunting
logsource:
    category: file_event
    product: windows
    definition: 'Requirements: By default the file_event log source might not contain the IntegrityLevel of the Process. It should be collected in order to use this rule'
detection:
    selection:
        TargetFilename|contains: ':\Windows\System32\CodeIntegrity\'
        TargetFilename|endswith:
            - '.cip'
            - '.p7b'
        IntegrityLevel: 'High'
    condition: selection
falsepositives:
    - May occur legitimately as part of admin activity, but rarely with interactive elevation.
level: medium