Winlogon Notify Key Logon Persistence

Severity: high
Author: frack113
Source: upstream

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 coverage

Tactic	Techniques
Persistence	`T1547.004` Boot or Logon Autostart Execution: Winlogon Helper DLL
Privilege Escalation	`T1547.004` Boot or Logon Autostart Execution: Winlogon Helper DLL

Event coverage

Provider	Event ID	Title
Sysmon	13	RegistryEvent (Value Set)

Stages and Predicates

Stage 1: `selection`

Details|endswith: .dll
TargetObject|endswith: '\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\Notify\logon'

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.