Windows Registry Dotnet ETW Disabled Via ENV Variable

name: Windows Registry Dotnet ETW Disabled Via ENV Variable
id: 55502381-5cce-491b-9277-7cb1d10bc0df
version: 11
creation_date: '2021-10-07'
modification_date: '2026-08-05'
author: Nasreddine Bencherchali, Splunk
status: production
type: TTP
description: |-
    The following analytic detects a registry modification that disables the ETW for the .NET Framework.
    It leverages data from the Endpoint.Registry data model, specifically monitoring changes to the COMPlus_ETWEnabled registry value under the "Environment" registry key path for both user (HKCU\Environment) and machine (HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Environment) scopes.
    This activity is significant because disabling ETW can allow attackers to evade Endpoint Detection and Response (EDR) tools and hide their execution from audit logs.
    If confirmed malicious, this action could enable attackers to operate undetected, potentially leading to further compromise and persistent access within the environment.
data_source:
    - Sysmon EventID 13
search: |-
    | tstats `security_content_summariesonly`
      count min(_time) as firstTime
            max(_time) as lastTime

    FROM datamodel=Endpoint.Registry WHERE

    Registry.registry_path="*\\Environment*"
    Registry.registry_value_name="COMPlus_ETWEnabled"
    Registry.registry_value_data IN ("0x00000000", "0")

    by Registry.action Registry.dest Registry.process_guid Registry.process_id
       Registry.registry_hive Registry.registry_path Registry.registry_key_name
       Registry.registry_value_data Registry.registry_value_name
       Registry.registry_value_type Registry.status
       Registry.user Registry.vendor_product

    | `drop_dm_object_name(Registry)`
    | where isnotnull(registry_value_data)
    | `security_content_ctime(firstTime)`
    | `security_content_ctime(lastTime)`
    | `windows_registry_dotnet_etw_disabled_via_env_variable_filter`
how_to_implement: To successfully implement this search, you need to be ingesting logs with the registry value name, registry path, and registry value data from your endpoints. If you are using Sysmon, you must have at least version 2.0 of the official Sysmon TA. https://splunkbase.splunk.com/app/5709
known_false_positives: |-
    Setting the "COMPlus_ETWEnabled" value as a global environment variable either in user or machine scope should only happen during debugging use cases, hence the false positives rate should be very minimal.
references:
    - https://gist.github.com/Cyb3rWard0g/a4a115fd3ab518a0e593525a379adee3
    - https://blog.xpnsec.com/hiding-your-dotnet-complus-etwenabled/
    - https://attack.mitre.org/techniques/T1562/006/
drilldown_searches:
    - name: View the detection results for - "$dest$" and "$user$"
      search: '%original_detection_search% | search  dest = "$dest$" user = "$user$"'
      earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
    - name: View risk events for the last 7 days for - "$dest$" and "$user$"
      search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$dest$", "$user$") | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`'
      earliest_offset: 7d
      latest_offset: "0"
finding:
    title: The registry key [$registry_path$] with the value name [$registry_value_name$] was modified to the value [$registry_value_data$] to disable the ETW for the .NET Framework in [$dest$]
    entity:
        field: user
        type: user
        score: 50
intermediate_findings:
    entities:
        - field: dest
          type: system
          score: 50
          message: The registry key [$registry_path$] with the value name [$registry_value_name$] was modified to the value [$registry_value_data$] to disable the ETW for the .NET Framework in [$dest$]
analytic_story:
    - Windows Registry Abuse
    - Windows Defense Evasion Tactics
asset_type: Endpoint
mitre_attack_id:
    - T1685
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: endpoint
security_domain: endpoint
tests:
    - name: True Positive Test
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1562.006/dotnet_etw_bypass/dotnet_etw_bypass.log
          source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
          sourcetype: XmlWinEventLog
      test_type: unit