PowerShell ScriptBlock Winlogon Registry Modification via CurrentVersion\Winlogon

Detects PowerShell script blocks that modify Winlogon helper registry keys via Set-ItemProperty or New-Item on Windows.

FreeReviewedSigma · Medium · v2
Product
windows
Category
ps_script
Author
Timur Zinniatullin, oscd.community (SigmaHQ), DRL 1.1
Published
2019-10-21
Updated
2026-07-31
title: PowerShell ScriptBlock Winlogon Registry Modification via CurrentVersion\Winlogon
id: 19a191af-1d44-487a-b0ea-68606438497b
status: test
description: This rule identifies PowerShell activity where script block text references the Winlogon registry path under CurrentVersion\Winlogon. It also requires the script to include common registry modification commands (Set-ItemProperty and New-Item) and the creation of new items (New-Item). Because Winlogon helper settings can influence what programs Winlogon loads, malicious use of these paths may enable persistence or privilege impact. The detection relies on PowerShell Script Block Logging telemetry capturing the script block content.
references:
  - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1547.004/T1547.004.md
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/powershell/powershell_script/posh_ps_winlogon_helper_dll.yml
author: Timur Zinniatullin, oscd.community, Huntrule Team
date: 2019-10-21
modified: 2022-07-07
tags:
  - attack.privilege-escalation
  - attack.persistence
  - attack.t1547.004
logsource:
  product: windows
  category: ps_script
  definition: "Requirements: Script Block Logging must be enabled"
detection:
  selection:
    ScriptBlockText|contains: CurrentVersion\Winlogon
  selection2:
    ScriptBlockText|contains:
      - Set-ItemProperty
      - New-Item
  condition: all of selection*
falsepositives:
  - Unknown
level: medium
license: DRL-1.1
related:
  - id: 851c506b-6b7c-4ce2-8802-c703009d03c0
    type: derived