Sigma rule: DMSA Service Account Created in Specific OUs - PowerShell

Rule

Title

DMSA Service Account Created in Specific OUs - PowerShell

Status

experimental

Level

medium

Author

Swachchhanda Shrawan Poudel (Nextron Systems)

Date

2025-05-24

File

rules/windows/powershell/powershell_script/posh_ps_create_new_dmsasvc_account.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

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.

Log source

product

windows

category

ps_script

Detection

selection:
    ScriptBlockText|contains|all:
        - 'New-ADServiceAccount'
        - '-CreateDelegatedServiceAccount'
        - '-path'
condition: selection

False positives (as the rule lists them)

• Unknown

Tags

• attack.privilege-escalation
• attack.initial-access
• attack.persistence
• attack.stealth
• attack.t1078.002
• attack.t1098

MITRE ATT&CK ids this rule names

• T1078.002
• T1098

Related rules

• e15bc294-ae2a-45ad-b7d6-637b33868bde (similar)
• 0ea8db81-2ff6-4525-9448-33bbe7effc13 (similar)

References

• https://www.akamai.com/blog/security-research/abusing-bad-successor-for-privilege-escalation-in-active-directory

Read on 2026-11-03T00:58:21.399Z under licence sigma-drl-1.1@d5f4c36a from https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/powershell/powershell_script/posh_ps_create_new_dmsasvc_account.yml