SigmaHQ/rules/windows/builtin/win_alert_ad_user_backdoors.yml

title: Active Directory User Backdoors
description: Detects scenarios where one can control another users or computers account without having to use their credentials.
references:
    - https://msdn.microsoft.com/en-us/library/cc220234.aspx
    - https://adsecurity.org/?p=3466
    - https://www.harmj0y.net/blog/redteaming/another-word-on-delegation/
author: '@neu5ron'
tags:
    - attack.t1098
    - attack.credential_access
    - attack.persistence
logsource:
    product: windows
    service: security
    definition1: 'Requirements: Audit Policy : Account Management > Audit User Account Management, Group Policy : Computer Configuration\Windows Settings\Security Settings\Advanced Audit Policy Configuration\Audit Policies\Account Management\Audit User Account Management'
    definition2: 'Requirements: Audit Policy : DS Access > Audit Directory Service Changes, Group Policy : Computer Configuration\Windows Settings\Security Settings\Advanced Audit Policy Configuration\Audit Policies\DS Access\Audit Directory Service Changes'
detection:
    selection1:
        EventID: 4738
    filter1:
        AllowedToDelegateTo: null
    selection2:
        EventID: 5136
        AttributeLDAPDisplayName: 'msDS-AllowedToDelegateTo'
    selection3:
        EventID: 5136
        ObjectClass: 'user'
        AttributeLDAPDisplayName: 'servicePrincipalName'
    selection4:
        EventID: 5136
        AttributeLDAPDisplayName: 'msDS-AllowedToActOnBehalfOfOtherIdentity'        
    condition: (selection1 and not filter1) or selection2 or selection3 or selection4
falsepositives: 
    - Unknown
level: high