Sigma rule: DotNet CLR DLL Loaded By Scripting Applications

Rule

Title

DotNet CLR DLL Loaded By Scripting Applications

Status

test

Level

high

Author

omkar72, oscd.community

Date

2020-10-14

Modified

2023-02-23

File

rules/windows/image_load/image_load_susp_script_dotnet_clr_dll_load.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects .NET CLR DLLs being loaded by scripting applications such as wscript or cscript. This could be an indication of potential suspicious execution.

Log source

product

windows

category

image_load

Detection

selection:
    Image|endswith:
        - '\cmstp.exe'
        - '\cscript.exe'
        - '\mshta.exe'
        - '\msxsl.exe'
        - '\regsvr32.exe'
        # - '\svchost.exe'
        - '\wmic.exe'
        - '\wscript.exe'
    ImageLoaded|endswith:
        - '\clr.dll'
        - '\mscoree.dll'
        - '\mscorlib.dll'
condition: selection

False positives (as the rule lists them)

• Unknown

Tags

• attack.execution
• attack.privilege-escalation
• attack.stealth
• attack.t1055

MITRE ATT&CK ids this rule names

• T1055

References

• https://github.com/tyranid/DotNetToJScript
• https://thewover.github.io/Introducing-Donut/
• https://web.archive.org/web/20230329154538/https://blog.menasec.net/2019/07/interesting-difr-traces-of-net-clr.html
• https://web.archive.org/web/20221026202428/https://gist.github.com/code-scrap/d7f152ffcdb3e0b02f7f394f5187f008

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_susp_script_dotnet_clr_dll_load.yml