Windows Winlogon Notify Registry Key DLL Persistence (logon)

title: Windows Winlogon Notify Registry Key DLL Persistence (logon)
id: 2b6f5534-ef2b-4c37-a099-ab0aa4e6820b
status: test
description: This rule flags registry changes that set Winlogon Notify logon entries whose Details value ends with a DLL file extension. Abuse of Winlogon Notify can cause code execution during user logon, making it a useful persistence mechanism for attackers. The detection relies on registry set telemetry capturing TargetObject paths under Winlogon\Notify\logon and the stored Details value.
references:
  - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1547.004/T1547.004.md#atomic-test-3---winlogon-notify-key-logon-persistence---powershell
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/registry/registry_set/registry_set_winlogon_notify_key.yml
author: frack113, Huntrule Team
date: 2021-12-30
modified: 2023-08-17
tags:
  - attack.privilege-escalation
  - attack.persistence
  - attack.t1547.004
logsource:
  category: registry_set
  product: windows
detection:
  selection:
    TargetObject|endswith: \SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\Notify\logon
    Details|endswith: .dll
  condition: selection
falsepositives:
  - Unknown
level: high
license: DRL-1.1
related:
  - id: bbf59793-6efb-4fa1-95ca-a7d288e52c88
    type: derived