ATT&CK coverage › Technique

Boot or Logon Autostart Execution: Winlogon Helper DLL T1547.004

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 <code>HKLM\Software[\\Wow6432Node\\]\Microsoft\Windows NT\CurrentVersion\Winlogon\</code> and <code>HKCU\Software\Microsoft\Windows NT\CurrentVersion\Winlogon\</code> are used to manage additional helper programs and functionalities that support Winlogon.

Events covered

2 catalog events are tagged with this technique by at least one rule.

ProviderEvent IDTitle
Sysmon13RegistryEvent (Value Set)
PowerShell4104Creating Scriptblock text (MessageNumber of MessageTotal).

Authoring guide

Patterns shared across the 2 rules above: which fields they filter on, what specific values they look for, and what they exclude. Field names are normalized across vendors so Sigma's Image, Elastic's process.name, and Splunk's process_name collapse into one row. Each rule contributes at most once per row.

Fields filtered most (3 distinct)

The fields most rules look at when detecting this technique. The How column shows the operators authors use (eq, wildcard, regex_match, match) and how often each appears. Sample values are concrete examples to start from, not an exhaustive list.

FieldRulesHowSample values
ScriptBlockText1match 1New-Item, CurrentVersion\Winlogon, Set-ItemProperty
Details1ends_with 1.dll
TargetObject1ends_with 1\SOFTWARE\Microsoft\Windows...

Top indicator values (5 distinct)

Specific (field, operator, value) combinations the rules check for, ranked by how many rules under this technique use each one. The Corpus reach column counts how many rules across the entire catalog (any technique) check the same combination. High numbers point to widely-used indicators that are likely noisy on their own; combine them with another condition for useful signal. Blank means the combination is specific to rules under this technique.

FieldKindValueRules (here)Corpus reach
ScriptBlockTextmatchSet-ItemProperty1
ScriptBlockTextmatchNew-Item1
ScriptBlockTextmatchCurrentVersion\Winlogon1
TargetObjectends_with\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\Notify\logon1
Detailsends_with.dll13

Rules under this technique

Every rule in the catalog tagged with this technique, grouped by vendor. Click a rule title for its full predicates, exclusions, and indicators.

Sigma 2 rules