DMSA Service Account Created in Specific OUs - PowerShell

Detects the creation of a dMSA service account using the New-ADServiceAccount cmdlet in certain OUs. The fact that the cmdlet is used 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 abuse of the BaDSuccessor vulnerability for privilege escalation within the Windows Server 2025 Active Directory environment.

View on GitHub Open raw file

Detection logic

selection

ScriptBlockText|contains|all:
  - New-ADServiceAccount
  - -CreateDelegatedServiceAccount
  - -path

Condition

selection

Raw YAML

title: DMSA Service Account Created in Specific OUs - PowerShell
id: 02122374-b74e-495c-b285-9e4da973f3d6
related:
    - id: e15bc294-ae2a-45ad-b7d6-637b33868bde # Windows Security Creation of New MsDS-DelegatedManagedServiceAccount (DMSA) Object
      type: similar
    - id: 0ea8db81-2ff6-4525-9448-33bbe7effc13 # Process Creation Detection
      type: similar
status: experimental
description: |
    Detects the creation of a dMSA service account using the New-ADServiceAccount cmdlet in certain OUs.
    The fact that the cmdlet is used 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 abuse of the BaDSuccessor vulnerability for privilege escalation within the Windows Server 2025 Active Directory environment.
references:
    - https://www.akamai.com/blog/security-research/abusing-bad-successor-for-privilege-escalation-in-active-directory
author: Swachchhanda Shrawan Poudel (Nextron Systems)
date: 2025-05-24
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