Detection: Windows Chromium Browser with Custom User Data Directory

Updated Date: 2025-05-26 ID: 4f546cf4-15aa-4368-80f7-940e92bc551e Author: Teoderick Contreras, Splunk Type: Anomaly Product: Splunk Enterprise Security

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.

 1
 2| tstats `security_content_summariesonly` min(_time) as firstTime max(_time)
 3as lastTime from datamodel=Endpoint.Processes where 
 4Processes.process_name IN ("Chrome.exe","Brave.exe", "Opera.exe", "Vivaldi.exe", "msedge.exe")
 5Processes.process = "*--user-data-dir*" 
 6Processes.process IN ("*--disable-gpu*", "*--disable-3d-apis*")
 7by Processes.action Processes.dest Processes.original_file_name Processes.parent_process
 8Processes.parent_process_exec Processes.parent_process_guid Processes.parent_process_id
 9Processes.parent_process_name Processes.parent_process_path Processes.process Processes.process_exec
10Processes.process_guid Processes.process_hash Processes.process_id Processes.process_integrity_level
11Processes.process_name Processes.process_path Processes.user Processes.user_id Processes.vendor_product
12
13| `drop_dm_object_name(Processes)` 
14
15| `security_content_ctime(firstTime)` 
16
17| `security_content_ctime(lastTime)` 
18
19| `windows_chromium_browser_with_custom_user_data_directory_filter`

Data Source

Name Platform Sourcetype Source
CrowdStrike ProcessRollup2 N/A 'crowdstrike:events:sensor' 'crowdstrike'
Sysmon EventID 1 Windows icon Windows 'xmlwineventlog' 'XmlWinEventLog:Microsoft-Windows-Sysmon/Operational'
Windows Event Log Security 4688 Windows icon Windows 'xmlwineventlog' 'XmlWinEventLog:Security'

Macros Used

Name Value
security_content_ctime convert timeformat="%Y-%m-%dT%H:%M:%S" ctime($field$)
windows_chromium_browser_with_custom_user_data_directory_filter search *
windows_chromium_browser_with_custom_user_data_directory_filter is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Annotations

- MITRE ATT&CK
+ Kill Chain Phases
+ NIST
+ CIS
- Threat Actors
ID Technique Tactic
T1497 Virtualization/Sandbox Evasion Defense Evasion
Exploitation
DE.AE
CIS 10

Default Configuration

This detection is configured by default in Splunk Enterprise Security to run with the following settings:

Setting Value
Disabled true
Cron Schedule 0 * * * *
Earliest Time -70m@m
Latest Time -10m@m
Schedule Window auto
Creates Risk Event True
This configuration file applies to all detections of type anomaly. These detections will use Risk Based Alerting.

Implementation

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.

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message:

A chromium process with the --user-data-dir flag was launched on $dest$ by user $user$.

Risk Object Risk Object Type Risk Score Threat Objects
dest system 40 parent_process_name

References

Detection Testing

Test Type Status Dataset Source Sourcetype
Validation ✅ Passing N/A N/A N/A
Unit ✅ Passing Dataset XmlWinEventLog:Microsoft-Windows-Sysmon/Operational XmlWinEventLog
Integration ✅ Passing Dataset XmlWinEventLog:Microsoft-Windows-Sysmon/Operational XmlWinEventLog

Replay any dataset to Splunk Enterprise by using our replay.py tool or the UI. Alternatively you can replay a dataset into a Splunk Attack Range

Source: GitHub | Version: 1