ETW Logging Tamper In .NET Processes Via CommandLine

Description

Detects changes to environment variables related to ETW logging via the CommandLine. This could indicate potential adversaries stopping ETW providers recording loaded .NET assemblies.

Query · sigma

selection:
  CommandLine|contains:
  - COMPlus_ETWEnabled
  - COMPlus_ETWFlags
condition: selection

Known false positives

  • Unlikely
Raw source ETW Logging Tamper In .NET Processes Via CommandLine · Sigma
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Published by SigmaHQ/sigma ↗, licensed under Detection Rule License 1.1 ↗. Reproduced here unmodified. 
title: ETW Logging Tamper In .NET Processes Via CommandLine
id: 41421f44-58f9-455d-838a-c398859841d4
status: test
description: |
    Detects changes to environment variables related to ETW logging via the CommandLine.
    This could indicate potential adversaries stopping ETW providers recording loaded .NET assemblies.
references:
    - https://twitter.com/_xpn_/status/1268712093928378368
    - https://social.msdn.microsoft.com/Forums/vstudio/en-US/0878832e-39d7-4eaf-8e16-a729c4c40975/what-can-i-use-e13c0d23ccbc4e12931bd9cc2eee27e4-for?forum=clr
    - https://github.com/dotnet/runtime/blob/ee2355c801d892f2894b0f7b14a20e6cc50e0e54/docs/design/coreclr/jit/viewing-jit-dumps.md#setting-configuration-variables
    - https://github.com/dotnet/runtime/blob/f62e93416a1799aecc6b0947adad55a0d9870732/src/coreclr/src/inc/clrconfigvalues.h#L35-L38
    - https://github.com/dotnet/runtime/blob/7abe42dc1123722ed385218268bb9fe04556e3d3/src/coreclr/src/inc/clrconfig.h#L33-L39
    - https://github.com/dotnet/runtime/search?p=1&q=COMPlus_&unscoped_q=COMPlus_
    - https://bunnyinside.com/?term=f71e8cb9c76a
    - http://managed670.rssing.com/chan-5590147/all_p1.html
    - https://github.com/dotnet/runtime/blob/4f9ae42d861fcb4be2fcd5d3d55d5f227d30e723/docs/coding-guidelines/clr-jit-coding-conventions.md#1412-disabling-code
    - https://i.blackhat.com/EU-21/Wednesday/EU-21-Teodorescu-Veni-No-Vidi-No-Vici-Attacks-On-ETW-Blind-EDRs.pdf
author: Roberto Rodriguez (Cyb3rWard0g), OTR (Open Threat Research)
date: 2020-05-02
modified: 2022-12-09
tags:
    - attack.defense-impairment
    - attack.t1685
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        CommandLine|contains:
            - 'COMPlus_ETWEnabled'
            - 'COMPlus_ETWFlags'
    condition: selection
falsepositives:
    - Unlikely
level: high

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