Sigma rule: DLL Loaded From Suspicious Location Via Cmspt.EXE

Rule

Title

DLL Loaded From Suspicious Location Via Cmspt.EXE

Status

test

Level

high

Author

Nasreddine Bencherchali (Nextron Systems)

Date

2022-08-30

Modified

2023-02-17

File

rules/windows/image_load/image_load_cmstp_load_dll_from_susp_location.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects cmstp loading "dll" or "ocx" files from suspicious locations

Log source

product

windows

category

image_load

Detection

selection:
    Image|endswith: '\cmstp.exe'
    ImageLoaded|contains:
        # Add more suspicious paths as you see fit in your env
        - '\PerfLogs\'
        - '\ProgramData\'
        - '\Users\'
        - '\Windows\Temp\'
        - 'C:\Temp\'
    ImageLoaded|endswith:
        - '.dll'
        - '.ocx'
condition: selection

False positives (as the rule lists them)

• Unikely

Tags

• attack.stealth
• attack.t1218.003

MITRE ATT&CK ids this rule names

• T1218.003

References

• https://github.com/vadim-hunter/Detection-Ideas-Rules/blob/02bcbfc2bfb8b4da601bb30de0344ae453aa1afe/TTPs/Defense%20Evasion/T1218%20-%20Signed%20Binary%20Proxy%20Execution/T1218.003%20-%20CMSTP/Procedures.yaml

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/image_load/image_load_cmstp_load_dll_from_susp_location.yml