Windows PowerShell Modifies dMSA msDS-ManagedAccountPrecededByLink Attributes

Flags PowerShell script content modifying msDS-ManagedAccountPrecededByLink (dMSA link attributes) via AD link changes.

FreeReviewedSigma · Low · v2
Product
windows
Category
ps_script
Author
Swachchhanda Shrawan Poudel (Nextron Systems) (SigmaHQ), DRL 1.1
Published
2025-05-24
Updated
2026-07-31
title: Windows PowerShell Modifies dMSA msDS-ManagedAccountPrecededByLink Attributes
id: 3c4dbe53-1130-4c7c-a3ed-bae6b11f500c
related:
  - id: 6c9eb492-e477-4df9-b0f4-571fc9db29cd
    type: similar
  - id: 9b111d8e-92e0-4153-88bc-daefc1333aba
    type: derived
status: experimental
description: This rule flags PowerShell script text that modifies dMSA link attributes by targeting msDS-ManagedAccountPrecededByLink. Attackers may abuse directory link attributes to establish or alter relationships that can support privilege escalation or persistence. It relies on PowerShell ScriptBlockText telemetry to match specific string fragments indicating the targeted attribute and distinguished name components.
references:
  - https://www.akamai.com/blog/security-research/abusing-bad-successor-for-privilege-escalation-in-active-directory
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/powershell/powershell_script/posh_ps_modification_of_dmsa_link_attribute.yml
author: Swachchhanda Shrawan Poudel (Nextron Systems), Huntrule Team
date: 2025-05-24
tags:
  - attack.privilege-escalation
  - attack.persistence
  - attack.initial-access
  - attack.stealth
  - attack.t1078.002
  - attack.t1098
logsource:
  category: ps_script
  product: windows
detection:
  selection:
    ScriptBlockText|contains|all:
      - .Put("msDS-ManagedAccountPrecededByLink
      - CN=
  condition: selection
falsepositives:
  - Legitimate administrative tasks modifying these attributes.
level: low
license: DRL-1.1