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. [1]
攻撃者は、プロセスにロードされたAppCert DLLをトリガーとして悪意のあるコンテンツを実行することにより、永続性を確立したり権限を昇格させたりすることができます。HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Session Manager\のAppCertDLLs レジストリキーで特定されるDllは広く使われているアプリケーションプログラミングインターフェース（API）関数であるCreateProcess、CreateProcessAsUser、CreateProcessWithLoginW、CreateProcessWithTokenW、WinExecを呼び出すすべてのプロセスで読み込まれます[1]
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.
プロセスインジェクションと同様に、この値を悪用して、悪意のあるDLLをロードさせ、コンピュータ上の別のプロセスのコンテキストで実行させることで、昇格した権限を取得することが可能です。また、悪意のあるAppCert DLLは、APIアクティビティによって継続的にトリガーされることで、永続性を提供することがあります。
| ID | Name | Description |
|---|---|---|
| S0196 | PUNCHBUGGY |
PUNCHBUGGY can establish using a AppCertDLLs Registry key.[2] |
| ID | Mitigation | Description |
|---|---|---|
| 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 [3] tools, like Windows Defender Application Control[4], AppLocker, [5] [6] or Software Restriction Policies [7] where appropriate. [8] |
| ID | Data Source | Data Component | Detects |
|---|---|---|---|
| DS0017 | Command | Command Execution |
Monitor executed commands and arguments that may establish persistence and/or elevate privileges by executing malicious content triggered by AppCert DLLs loaded into processes. |
| DS0011 | Module | Module Load |
Monitor DLL loads by processes, specifically looking for DLLs that are not recognized or not normally loaded into a process. Tools such as Sysinternals Autoruns may overlook AppCert DLLs as an auto-starting location. [9] [10] |
| DS0009 | Process | OS API Execution |
Monitor and analyze application programming interface (API) calls that are indicative of Registry edits, such as |
| Process Creation |
Monitor newly executed processes that may establish persistence and/or elevate privileges by executing malicious content triggered by AppCert DLLs loaded into processes. |
||
| DS0024 | Windows Registry | Windows Registry Key Modification |
Monitor the AppCertDLLs Registry value for modifications that do not correlate with known software, patch cycles, etc. |