SigmaHQ/rules/windows/builtin/win_alert_ad_user_backdoors.yml

title: Active Directory User Backdoors
description: Detects scenarios where one can control another users account without having to use their credentials via msDS-AllowedToDelegateTo and or service principal names (SPN).
reference:
    -https://msdn.microsoft.com/en-us/library/cc220234.aspx
    -https://adsecurity.org/?p=3466
author: @neu5ron
logsource:
    product: windows
    service: security
    description1: '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'
    description2: '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
        AllowedToDelegateTo: *
    selection2:
        EventID: 5136
        AttributeLDAPDisplayName: 'msDS-AllowedToDelegateTo'
    selection3:
        EventID: 5136
        ObjectClass: 'user'
        AttributeLDAPDisplayName: 'servicePrincipalName'
    condition: selection1 or selection2 or selection3
falsepositives: 
    - Unknown
level: high