DMSA Service Account Created in Specific OUs - PowerShell

SIGMA detection rule by Swachchhanda Shrawan Poudel (Nextron Systems) · NOASSERTION

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.

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

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877deac3-351f-4a18-9949-e3259a1c014e

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