Cross-source coverage

T1547.004 / ATT&CK

Boot or Logon Autostart Execution: Winlogon Helper DLL

5 rules across 2 sources.

From MITRE ATT&CK 19.2

Adversaries may abuse features of Winlogon to execute DLLs and/or executables when a user logs in. Winlogon.exe is a Windows component responsible for actions at logon/logoff as well as the secure attention sequence (SAS) triggered by Ctrl-Alt-Delete. Registry entries in HKLM\Software[\\Wow6432Node\\]\Microsoft\Windows NT\CurrentVersion\Winlogon\ and HKCU\Software\Microsoft\Windows NT\CurrentVersion\Winlogon\ are used to manage additional helper programs and functionalities that support Winlogon.

Malicious modifications to these Registry keys may cause Winlogon to load and execute malicious DLLs and/or executables. Specifically, the following subkeys have been known to be possibly vulnerable to abuse:

  • Winlogon\Notify - points to notification package DLLs that handle Winlogon events
  • Winlogon\Userinit - points to userinit.exe, the user initialization program executed when a user logs on
  • Winlogon\Shell - points to explorer.exe, the system shell executed when a user logs on

Adversaries may take advantage of these features to repeatedly execute malicious code and establish persistence.

Platforms
Windows
Telemetry
WinEventLog:SysmonWinEventLog:SecurityAutoruns:RegistryScan

How MITRE says to detect it DET0404

Detect Winlogon Helper DLL Abuse via Registry and Process Artifacts on Windows

Windows Analytic 1133

Monitor Windows Registry modifications to Winlogon keys (Shell, Userinit, Notify) that introduce new executable or DLL paths. Correlate these changes with subsequent DLL loading, image loads, or process creation originating from winlogon.exe or userinit.exe. Abnormal child process lineage or unauthorized binaries in C:\Windows\System32 may indicate abuse.

  • WinEventLog:Sysmon EventCode=7
  • WinEventLog:Sysmon EventCode=1
  • WinEventLog:Security modification to Winlogon registry keys such as Shell, Notify, or Userinit
  • Autoruns:RegistryScan Enumerate Winlogon subkeys for unknown or unsigned binaries

SigmaHQ/sigma

4 rules
Detection Severity Format
Winlogon Notify Key Logon Persistence High Sigma
MITRE BZAR Indicators for Persistence Medium Sigma
TanStack Supply-Chain Attack File Creation Indicators - Linux Medium Sigma
Winlogon Helper DLL Medium Sigma

elastic/detection-rules

1 rule
Detection Severity Format
Persistence via WMI Standard Registry Provider High Elastic TOML

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