ATT&CK coverage › Technique

Event Triggered Execution: AppInit DLLs T1546.010

Adversaries may establish persistence and/or elevate privileges by executing malicious content triggered by AppInit DLLs loaded into processes. Dynamic-link libraries (DLLs) that are specified in the <code>AppInit_DLLs</code> value in the Registry keys <code>HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\Windows</code> or <code>HKEY_LOCAL_MACHINE\Software\Wow6432Node\Microsoft\Windows NT\CurrentVersion\Windows</code> are loaded by user32.dll into every process that loads user32.dll. In practice this is nearly every program, since user32.dll is a very common library.

Events covered

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

ProviderEvent IDTitle
Sysmon12RegistryEvent (Object create and delete)
Sysmon13RegistryEvent (Value Set)
Sysmon14RegistryEvent (Key and Value Rename)

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 (5 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
TargetObject2match 1, ends_with 1\\Windows NT\\CurrentVersion\\Windows\\AppInit_DLLs, \SOFTWARE\Wow6432Node\Microsoft\Windows..., \SOFTWARE\Microsoft\Windows...
EventLog1eq 1Microsoft-Windows-Sysmon/Operational
EventID1eq 113
Details1eq 1(Empty)
NewName1ends_with 1\SOFTWARE\Wow6432Node\Microsoft\Windows..., \SOFTWARE\Microsoft\Windows...

Top indicator values (8 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
EventLogeqMicrosoft-Windows-Sysmon/Operational1
EventIDeq131
TargetObjectmatch\\Windows NT\\CurrentVersion\\Windows\\AppInit_DLLs1
TargetObjectends_with\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Windows\AppInit_Dlls1
NewNameends_with\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Windows\AppInit_Dlls1
Detailseq(Empty)124
TargetObjectends_with\SOFTWARE\Wow6432Node\Microsoft\Windows NT\CurrentVersion\Windows\AppInit_Dlls1
NewNameends_with\SOFTWARE\Wow6432Node\Microsoft\Windows NT\CurrentVersion\Windows\AppInit_Dlls1

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 1 rule

Kusto Query Language 1 rule