T1546.009sub-technique of T1546 Event Triggered Execution

AppCert DLLs

Windowsnothing on this site yetT1546.009 on attack.mitre.org

Adversaries may establish persistence and/or elevate privileges by executing malicious content triggered by AppCert DLLs loaded into processes. Dynamic-link libraries (DLLs) that are specified in the `AppCertDLLs` Registry key under `HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Session Manager\` are loaded into every process that calls the ubiquitously used application programming interface (API) functions `CreateProcess`, `CreateProcessAsUser`,...
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

Detection Strategy for AppCert DLLs Persistence via Registry Injection

Detection of AppCert DLL abuse involves correlating registry modifications to the AppCertDLLs key with subsequent unexpected DLL load behavior during process creation events.

what reduces it

M1038 Execution Prevention. Adversaries install new AppCertDLL binaries to execute this technique. Identify and block potentially malicious software executed through AppCertDLLs functionality by using application control tools, like Windows Defender Application Control, AppLocker, or Software Restriction Policies where appropriate.

the rest of T1546

T1546.001 Change Default File Association · not covered yet
T1546.002 Screensaver · not covered yet
T1546.003 Windows Management Instrumentation Event Subscription · 5 on this site
T1546.004 Unix Shell Configuration Modification · not covered yet
T1546.005 Trap · not covered yet
T1546.006 LC_LOAD_DYLIB Addition · not covered yet
T1546.007 Netsh Helper DLL · not covered yet
T1546.008 Accessibility Features · not covered yet
T1546.010 AppInit DLLs · not covered yet
T1546.011 Application Shimming · not covered yet
T1546.012 Image File Execution Options Injection · not covered yet
T1546.013 PowerShell Profile · not covered yet
T1546.014 Emond · not covered yet
T1546.015 Component Object Model Hijacking · not covered yet
T1546.016 Installer Packages · not covered yet
T1546.017 Udev Rules · not covered yet
T1546.018 Python Startup Hooks · 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.