Sigma rule: Registry-Free Process Scope COR_PROFILER

Rule

Title

Registry-Free Process Scope COR_PROFILER

Status

test

Level

medium

Author

frack113

Date

2021-12-30

File

rules/windows/powershell/powershell_script/posh_ps_cor_profiler.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

Adversaries may leverage the COR_PROFILER environment variable to hijack the execution flow of programs that load the .NET CLR.
The COR_PROFILER is a .NET Framework feature which allows developers to specify an unmanaged (or external of .NET) profiling DLL to be loaded into each .NET process that loads the Common Language Runtime (CLR).
These profiliers are designed to monitor, troubleshoot, and debug managed code executed by the .NET CLR.
(Citation: Microsoft Profiling Mar 2017)
(Citation: Microsoft COR_PROFILER Feb 2013)

Log source

product

windows

category

ps_script

definition

Requirements: Script Block Logging must be enabled

Detection

selection:
    ScriptBlockText|contains|all:
        - '$env:COR_ENABLE_PROFILING'
        - '$env:COR_PROFILER'
        - '$env:COR_PROFILER_PATH'
condition: selection

False positives (as the rule lists them)

• Legitimate administrative script

Tags

• attack.privilege-escalation
• attack.persistence
• attack.execution
• attack.stealth
• attack.t1574.012

MITRE ATT&CK ids this rule names

• T1574.012

References

• https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1574.012/T1574.012.md#atomic-test-3---registry-free-process-scope-cor_profiler

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/powershell/powershell_script/posh_ps_cor_profiler.yml