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.^[1]

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:^[1]

• 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.

References

1. Langendorf, S. (2013, September 24). Windows Registry Persistence, Part 2: The Run Keys and Search-Order. Retrieved November 17, 2024.

Gekoppelde issues

• MITREATTACK -

  EN: MITRE ATT&CK®, https://attack.mitre.org/. © 2026 The MITRE Corporation. This work is reproduced and distributed with the permission of The MITRE Corporation. License: The MITRE Corporation (MITRE) hereby grants you a non-exclusive, royalty-free license to use ATT&CK® for research, development, and commercial purposes. Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy. See the Terms of Use for the disclaimers. ATT&CK® is a registered trademark of The MITRE Corporation. Converted into the GRCA format.

  DE: MITRE ATT&CK®, https://attack.mitre.org/. © 2026 The MITRE Corporation. This work is reproduced and distributed with the permission of The MITRE Corporation. MITRE erlaubt die Nutzung für Forschung, Entwicklung und kommerzielle Zwecke, wenn jede Kopie den Urheberrechtsvermerk und die Lizenz enthält; maßgeblich ist der englische Wortlaut der Lizenz oben und die Terms of Use mit den Haftungsausschlüssen. ATT&CK® ist eine eingetragene Marke der MITRE Corporation. In das GRCA-Format umgewandelt.