CMSTP
Where this stands
One published detection covers this technique. Every one is unverified — no rule on Siemphony has been executed against real telemetry.
What the technique is
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.
Read it on attack.mitre.orgWhat MITRE says you would watch
- AN0932
Execution of CMSTP.exe with arguments pointing to suspicious or remote INF/SCT/DLL payloads, optionally followed by outbound network connections to untrusted IPs, process injection via COM interfaces (CMSTPLUA, CMLUAUTIL), registry modifications registering malicious profiles, or creation of suspicious INF/DLL/SCT files prior to execution.
Technique names and descriptions © MITRE ATT&CK®, CC BY 4.0. Not endorsed by MITRE.