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. (Citation: Microsoft Connection Manager Oct 2009) 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. (Citation: Twitter CMSTP Usage Jan 2018) Similar to Regsvr32 / ”Squiblydoo”, CMSTP.exe may be abused to load and execute DLLs (Citation: MSitPros CMSTP Aug 2017) and/or COM scriptlets (SCT) from remote servers. (Citation: Twitter CMSTP Jan 2018) (Citation: GitHub Ultimate AppLocker Bypass List) (Citation: Endurant CMSTP July 2018) 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. (Citation: MSitPros CMSTP Aug 2017) (Citation: GitHub Ultimate AppLocker Bypass List) (Citation: Endurant CMSTP July 2018)
View in MITRE ATT&CK®| Capability ID | Capability Description | Mapping Type | ATT&CK ID | ATT&CK Name |
|---|---|---|---|---|
| CM-11 | User-installed Software | Protects | T1218.003 | CMSTP |
| CM-2 | Baseline Configuration | Protects | T1218.003 | CMSTP |
| CM-6 | Configuration Settings | Protects | T1218.003 | CMSTP |
| CM-7 | Least Functionality | Protects | T1218.003 | CMSTP |
| CM-8 | System Component Inventory | Protects | T1218.003 | CMSTP |
| RA-5 | Vulnerability Monitoring and Scanning | Protects | T1218.003 | CMSTP |
| SI-10 | Information Input Validation | Protects | T1218.003 | CMSTP |
| SI-16 | Memory Protection | Protects | T1218.003 | CMSTP |
| SI-3 | Malicious Code Protection | Protects | T1218.003 | CMSTP |
| SI-4 | System Monitoring | Protects | T1218.003 | CMSTP |
| SI-7 | Software, Firmware, and Information Integrity | Protects | T1218.003 | CMSTP |
| action.hacking.variety.Abuse of functionality | Abuse of functionality. | related-to | T1218.003 | Signed Binary Proxy Execution: CMSTP |