Sigma rule: CMSTP App Paths Registry Key Modification

Rule

Title

CMSTP App Paths Registry Key Modification

Status

stable

Level

high

Author

Nik Seetharaman

Date

2018-07-16

Modified

2026-08-27

File

rules/windows/registry/registry_event/registry_event_cmstp_execution_by_registry.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects modifications to the CMSTP App Paths registry key. This may indicate abuse of
Microsoft Connection Manager Profile Installer (CMSTP) for arbitrary code execution or UAC bypass.

Log source

product

windows

category

registry_event

Detection

selection:
    TargetObject|contains: 'SOFTWARE\Microsoft\Windows\CurrentVersion\App Paths\cmmgr32.exe\'
filter_main_cmcfg32:
    TargetObject|endswith: 'SOFTWARE\Microsoft\Windows\CurrentVersion\App Paths\cmmgr32.exe\CmstpExtensionDll'
    Details:
        - 'C:\Windows\System32\cmcfg32.dll'
        - 'C:\Windows\SysWOW64\cmcfg32.dll'
filter_main_empty:
    Details: '(Empty)'
condition: selection and not 1 of filter_main_*

False positives (as the rule lists them)

• Legitimate CMSTP use (unlikely in modern enterprise environments)

Tags

• attack.execution
• attack.stealth
• attack.t1218.003
• attack.g0069
• car.2019-04-001

MITRE ATT&CK ids this rule names

• G0069
• T1218.003

References

• https://lolbas-project.github.io/lolbas/Binaries/Cmstp/
• https://web.archive.org/web/20190720093911/http://www.endurant.io/cmstp/detecting-cmstp-enabled-code-execution-and-uac-bypass-with-sysmon/
• https://web.archive.org/web/20190722224110/https://oddvar.moe/2017/08/15/research-on-cmstp-exe/

Read on 2026-11-03T00:58:21.399Z under licence sigma-drl-1.1@d5f4c36a from https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/registry/registry_event/registry_event_cmstp_execution_by_registry.yml