New DMSA Service Account Created in Specific OUs
Detects the creation of a dMSASvc 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.
Sigma rule (View on GitHub)
1title: New DMSA Service Account Created in Specific OUs
2id: 0ea8db81-2ff6-4525-9448-33bbe7effc13
3related:
4 - id: e15bc294-ae2a-45ad-b7d6-637b33868bde # Windows Security Creation of New MsDS-DelegatedManagedServiceAccount (DMSA) Object
5 type: similar
6 - id: 02122374-b74e-495c-b285-9e4da973f3d6 # ScriptBlockText Detection
7 type: similar
8status: experimental
9description: |
10 Detects the creation of a dMSASvc account using the New-ADServiceAccount cmdlet in certain OUs.
11 The fact that the Cmdlet is used to create a dMSASvc account in a specific OU is highly suspicious.
12 It is a pattern trying to exploit the BadSuccessor privilege escalation vulnerability in Windows Server 2025.
13 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,
14 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.
15references:
16 - https://www.akamai.com/blog/security-research/abusing-bad-successor-for-privilege-escalation-in-active-directory
17author: Swachchhanda Shrawan Poudel (Nextron Systems)
18date: 2025-05-24
19tags:
20 - attack.privilege-escalation
21 - attack.initial-access
22 - attack.defense-evasion
23 - attack.persistence
24 - attack.t1078.002
25 - attack.t1098
26logsource:
27 category: process_creation
28 product: windows
29detection:
30 selection_img:
31 - Image|endswith:
32 - '\powershell.exe'
33 - '\pwsh.exe'
34 - '\powershell_ise.exe'
35 - OriginalFileName:
36 - 'powershell.exe'
37 - 'pwsh.dll'
38 - 'powershell_ise.exe'
39 selection_cli:
40 CommandLine|contains|all:
41 - 'New-ADServiceAccount'
42 - '-CreateDelegatedServiceAccount'
43 - '-path'
44 condition: all of selection_*
45falsepositives:
46 - Unknown
47level: medium
References
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