Mmc.exe

Load snap-ins to locally and remotely manage Windows systems

Paths

• C:\Windows\System32\mmc.exe
• C:\Windows\SysWOW64\mmc.exe

Commands

Execute

Launch a 'backgrounded' MMC process and invoke a COM payload

Use case: Configure a snap-in to load a COM custom class (CLSID) that has been added to the registry

Privileges: User

mmc.exe -Embedding {PATH_ABSOLUTE:.msc}

UAC Bypass

Load an arbitrary payload DLL by configuring COR Profiler registry settings and launching MMC to bypass UAC.

Use case: Modify HKCU\Environment key in Registry with COR profiler values then launch MMC to load the payload DLL.

Privileges: Administrator

mmc.exe gpedit.msc

Download

Download and save an executable to disk

Use case: Download file from Internet

Privileges: User

mmc.exe -Embedding {PATH_ABSOLUTE:.msc}

Detection

• Sigma: https://github.com/SigmaHQ/sigma/blob/c04bef2fbbe8beff6c7620d5d7ea6872dbe7acba/rules/windows/process_creation/proc_creation_win_mmc_susp_child_process.yml
• Sigma: https://github.com/SigmaHQ/sigma/blob/c04bef2fbbe8beff6c7620d5d7ea6872dbe7acba/rules/windows/file/file_event/file_event_win_uac_bypass_dotnet_profiler.yml

Resources

• https://bohops.com/2018/08/18/abusing-the-com-registry-structure-part-2-loading-techniques-for-evasion-and-persistence/
• https://offsec.almond.consulting/UAC-bypass-dotnet.html
• https://www.youtube.com/watch?v=LFgZOTmhzeA