Windows Chromium Browser with Custom User Data Directory

name: Windows Chromium Browser with Custom User Data Directory
id: 4f546cf4-15aa-4368-80f7-940e92bc551e
version: 5
date: '2026-03-10'
author: Teoderick Contreras, Splunk
status: production
type: Anomaly
description: |
    The following analytic detects instances where the Chromium-based browser (e.g., Google Chrome, Microsoft Edge) is launched with the --user-data-dir command-line argument. While this flag is legitimate and used for multi-profile support or automation, it is frequently leveraged by malware and adversaries to run Chrome in an isolated environment for stealth operations, credential harvesting, phishing delivery, or evasion of user session artifacts.
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 IN ("Chrome.exe","Brave.exe", "Opera.exe", "Vivaldi.exe", "msedge.exe")
    Processes.process = "*--user-data-dir*"
    Processes.process IN ("*--disable-gpu*", "*--disable-3d-apis*")
    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_browser_with_custom_user_data_directory_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: Administrators may enable or disable this feature that may cause some false positive.
references:
    - https://chromium.googlesource.com/chromium/src/+/main/docs/user_data_dir.md
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 ("$user$", "$dest$") starthoursago=168  | 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: $info_min_time$
      latest_offset: $info_max_time$
rba:
    message: A chromium process with the --user-data-dir flag was launched on $dest$ by user $user$.
    risk_objects:
        - field: dest
          type: system
          score: 20
    threat_objects:
        - field: parent_process_name
          type: parent_process_name
tags:
    analytic_story:
        - StealC Stealer
        - Malicious Inno Setup Loader
        - Lokibot
    asset_type: Endpoint
    mitre_attack_id:
        - T1497
    product:
        - Splunk Enterprise
        - Splunk Enterprise Security
        - Splunk Cloud
    security_domain: endpoint
tests:
    - name: True Positive Test
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1497/chrom_no_sandbox/chrome-no_sandbox.log
          source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
          sourcetype: XmlWinEventLog