Event Triggered Execution: AppCert DLLs
- ID
- T1546.009
- Tactics
- TA0003 Persistence, TA0004 Privilege Escalation
- Sub-technique of
- T1546 Event Triggered Execution
- Platforms
- Windows
- Data sources
- Windows Registry Key Modification, Process Creation, Module Load
- Source
- attack.mitre.org
- MITRE last modified
- 25 Oct 2025
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, CreateProcessWithLoginW, CreateProcessWithTokenW, or WinExec. [7]
Similar to Process Injection, this value can be abused to obtain elevated privileges by causing a malicious DLL to be loaded and run in the context of separate processes on the computer. Malicious AppCert DLLs may also provide persistence by continuously being triggered by API activity.
Detection
- DET0362 Detection Strategy for AppCert DLLs Persistence via Registry Injection
Data components: Windows Registry Key Modification, Process Creation, Module Load
Mitigations (1)
- 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 [1] tools, like Windows Defender Application Control[2], AppLocker, [3] [4] or Software Restriction Policies [5] where appropriate. [6]
Software (1)
References
- Beechey 2010
- Microsoft Windows Defender Application Control
- Windows Commands JPCERT
- NSA MS AppLocker
- Corio 2008
- TechNet Applocker vs SRP
- Elastic Process Injection July 2017