T1547.004sub-technique of T1547 Boot or Logon Autostart Execution

Winlogon Helper DLL

Windowsnothing on this site yetT1547.004 on attack.mitre.org

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.
MITRE ATT&CK 19.2, retrieved 2026-09-12

If this is happening now

Checklists and playbooks to open while the alert is still live.

Playbook for this stage

Suspicious execution on an endpoint

An EDR alert, an unexplained process, or a user reporting something odd.

Playbook for this stage

Cloud account compromise

Impossible travel, an unrecognised inbox rule, or a reported invoice-fraud attempt.

how MITRE says to see it

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

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.

what reduces it

M1038 Execution Prevention. Identify and block potentially malicious software that may be executed through the Winlogon helper process by using application control tools like AppLocker that are capable of auditing and/or blocking unknown DLLs.
M1018 User Account Management. Limit the privileges of user accounts so that only authorized administrators can perform Winlogon helper changes.

the rest of T1547

T1547.001 Registry Run Keys / Startup Folder · 8 on this site
T1547.002 Authentication Package · not covered yet
T1547.003 Time Providers · not covered yet
T1547.005 Security Support Provider · not covered yet
T1547.006 Kernel Modules and Extensions · not covered yet
T1547.007 Re-opened Applications · not covered yet
T1547.008 LSASS Driver · not covered yet
T1547.009 Shortcut Modification · not covered yet
T1547.010 Port Monitors · not covered yet
T1547.012 Print Processors · not covered yet
T1547.013 XDG Autostart Entries · not covered yet
T1547.014 Active Setup · not covered yet
T1547.015 Login Items · not covered yet

The description, detection analytics and mitigations are reproduced from MITRE ATT&CK, version 19.2, under its terms of use. The checklists, hunts, labs and everything else linked here are this site’s.