System Binary Proxy Execution: CMSTP

Created the Saturday 04 March 2023. Updated 6 months, 2 weeks ago.

Adversaries may abuse CMSTP to proxy execution of malicious code. The Microsoft Connection Manager Profile Installer (CMSTP.exe) is a command-line program used to install Connection Manager service profiles. CMSTP.exe accepts an installation information file (INF) as a parameter and installs a service profile leveraged for remote access connections.

Adversaries may supply CMSTP.exe with INF files infected with malicious commands. Similar to Regsvr32 / "Squiblydoo", CMSTP.exe may be abused to load and execute DLLs and/or COM scriptlets (SCT) from remote servers. This execution may also bypass AppLocker and other application control defenses since CMSTP.exe is a legitimate binary that may be signed by Microsoft.

CMSTP.exe can also be abused to Bypass User Account Control and execute arbitrary commands from a malicious INF through an auto-elevated COM interface.

Technique Identifier

T1218.003

Technique Tags

Defense Evasion Microsoft Connection Manager Profile Installer (CMSTP.exe) INF files malicious COM scriptlets (SCT) malicious DLLs bypass AppLocker Bypass User Account Control

Additional Resources

External Links

The resources provided below are associated links that will give you even more detailed information and research on current evasion technique. It is important to note that, while these resources may be helpful, it is important to exercise caution when following external links. As always, be careful when clicking on links from unknown sources, as they may lead to malicious content.

System Binary Proxy Execution: CMSTP, Sub-technique T1218.003 - Enterprise | MITRE ATT&CK®