T1218.014

Description

Adversaries may abuse mmc.exe to proxy execution of malicious .msc files. Microsoft Management Console (MMC) is a binary that may be signed by Microsoft and is used in several ways in either its GUI or in a command prompt.

MMC can be used to create, open, and save custom consoles that contain administrative tools created by Microsoft, called snap-ins. These snap-ins may be used to manage Windows systems locally or remotely.

MMC can also be used to open Microsoft created .msc files to manage system configuration. For example, <code>mmc C:\Users\foo\admintools.msc /a</code> will open a custom, saved console msc file in author mode.

Another common example is <code>mmc gpedit.msc</code>, which will open the Group Policy Editor application window. Adversaries may use MMC commands to perform malicious tasks.

For example, <code>mmc wbadmin.msc delete catalog -quiet</code> deletes the backup catalog on the system (i.e. Inhibit System Recovery) without prompts to the user (Note: <code>wbadmin.msc</code> may only be present by default on Windows Server operating systems). Adversaries may also abuse MMC to execute malicious .msc files.

For example, adversaries may first create a malicious registry Class Identifier (CLSID) subkey, which uniquely identifies a Component Object Model class object. Then, adversaries may create custom consoles with the “Link to Web Address” snap-in that is linked to the malicious CLSID subkey.

Once the .msc file is saved, adversaries may invoke the malicious CLSID payload with the following command: <code>mmc.exe -Embedding C:\path\to\test.msc</code>.