Suspicious DMSA Service Account Created in Specific OUs - PowerShell (via ps_script)

title: Suspicious DMSA Service Account Created in Specific OUs - PowerShell (via ps_script)
id: 0b23c57c-d4ed-51bb-8b69-2ba855e585c3
status: stable
description: This rule detects the creation of a dMSA service account using the New-ADServiceAccount cmdlet in certain OUs. The fact that the cmdlet is leveraged to create a dMSASvc account in a specific OU is highly suspicious. It is a pattern trying to exploit the BadSuccessor privilege escalation vulnerability in Windows Server 2025. On top of that, if the user that is creating the dMSASvc account is not a legitimate administrator or does not have the necessary permissions, it is a strong signal of an attempted or successful misuse of the BaDSuccessor vulnerability for privilege escalation within the Windows Server 2025 Active Directory environment.
references:
    - https://attack.mitre.org/techniques/T1098/
    - https://attack.mitre.org/techniques/T1078/002/
    - https://www.akamai.com/blog/security-research/abusing-bad-successor-for-privilege-escalation-in-active-directory
author: Huntrule Team
date: 2026-04-18
tags:
    - attack.privilege-escalation
    - attack.initial-access
    - attack.persistence
    - attack.stealth
    - attack.t1078.002
    - attack.t1098
logsource:
    category: ps_script
    product: windows
detection:
    selection:
        ScriptBlockText|contains|all:
            - 'New-ADServiceAccount'
            - '-CreateDelegatedServiceAccount'
            - '-path'
    condition: selection
falsepositives:
    - Unknown
level: medium