Sigma rule: Potential DLL Sideloading Of MsCorSvc.DLL

Rule

Title

Potential DLL Sideloading Of MsCorSvc.DLL

Status

test

Level

medium

Author

Wietze Beukema

Date

2024-07-11

Modified

2025-02-26

File

rules/windows/image_load/image_load_side_load_mscorsvc.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects potential DLL sideloading of "mscorsvc.dll".

Log source

product

windows

category

image_load

Detection

selection:
    ImageLoaded|endswith: '\mscorsvc.dll'
filter_main_generic:
    ImageLoaded|startswith:
        - 'C:\Windows\Microsoft.NET\Framework\'
        - 'C:\Windows\Microsoft.NET\Framework64\'
        - 'C:\Windows\Microsoft.NET\FrameworkArm\'
        - 'C:\Windows\Microsoft.NET\FrameworkArm64\'
        - 'C:\Windows\WinSxS\'
condition: selection and not 1 of filter_main_*

False positives (as the rule lists them)

• Legitimate applications loading their own versions of the DLL mentioned in this rule.

Tags

• attack.privilege-escalation
• attack.persistence
• attack.execution
• attack.stealth
• attack.t1574.001

MITRE ATT&CK ids this rule names

• T1574.001

References

• https://hijacklibs.net/entries/microsoft/built-in/mscorsvc.html

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_side_load_mscorsvc.yml