Windows Chromium Process Loaded Extension via Command-Line

name: Windows Chromium Process Loaded Extension via Command-Line
id: 1b8a468a-52e3-4206-b14a-73165441684c
version: 5
creation_date: '2026-01-12'
modification_date: '2026-05-13'
author: Teoderick Contreras, Splunk
status: production
type: Anomaly
description: |
    The following analytic detects instances where Google Chrome is started with the --load-extension command-line flag, which allows loading unpacked or non-standard extensions. This behavior can indicate attempts to bypass enterprise extension policies, install malicious extensions, or load potentially harmful browser components. Monitoring such activity helps identify unauthorized extension usage, potential malware persistence mechanisms, or policy violations that could compromise browser security.
data_source:
    - Sysmon EventID 1
    - Windows Event Log Security 4688
    - CrowdStrike ProcessRollup2
search: |
    | tstats `security_content_summariesonly` min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where
    Processes.process_name = "Chrome.exe"
    Processes.process= "*--load-extension*"

    by Processes.action Processes.dest Processes.original_file_name Processes.parent_process
       Processes.parent_process_exec Processes.parent_process_guid Processes.parent_process_id
       Processes.parent_process_name Processes.parent_process_path Processes.process Processes.process_exec
       Processes.process_guid Processes.process_hash Processes.process_id Processes.process_integrity_level
       Processes.process_name Processes.process_path Processes.user Processes.user_id Processes.vendor_product
    | `drop_dm_object_name(Processes)`
    | `security_content_ctime(firstTime)`
    | `security_content_ctime(lastTime)`
    | `windows_chromium_process_loaded_extension_via_command_line_filter`
how_to_implement: |
    To successfully implement this search you need to be ingesting information
    on process that include the name of the process responsible for the changes from
    your endpoints into the `Endpoint` datamodel in the `Processes` node. In addition,
    confirm the latest CIM App 4.20 or higher is installed and the latest TA for the
    endpoint product.
known_false_positives: Developers or IT admins loading unpacked extensions for testing or deployment purposes.
references:
    - https://www.gdatasoftware.com/blog/2025/11/38298-learning-about-browser-hijacking
    - https://peter.sh/experiments/chromium-command-line-switches/
drilldown_searches:
    - name: View the detection results for - "$user$" and "$dest$"
      search: '%original_detection_search% | search  user = "$user$" dest = "$dest$"'
      earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
    - name: View risk events for the last 7 days for - "$user$" and "$dest$"
      search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$user$", "$dest$") | 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"
intermediate_findings:
    entities:
        - field: dest
          type: system
          score: 20
          message: $process_name$ was launched by $parent_process_name$ on $dest$ by user $user$ and attempted to load a browser extension via command-line $process$.
threat_objects:
    - field: parent_process_name
      type: parent_process_name
    - field: process
      type: process
    - field: process_name
      type: process_name
analytic_story:
    - Browser Hijacking
asset_type: Endpoint
mitre_attack_id:
    - T1185
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/T1185/chrome_load_extensions/chrome_load_extension.log
          source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
          sourcetype: XmlWinEventLog
      test_type: unit