Detection: Windows Chromium Process Loaded Extension via Command-Line

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.

 1
 2| tstats `security_content_summariesonly` min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where
 3Processes.process_name = "Chrome.exe"
 4Processes.process= "*--load-extension*"
 5
 6by Processes.action Processes.dest Processes.original_file_name Processes.parent_process
 7   Processes.parent_process_exec Processes.parent_process_guid Processes.parent_process_id
 8   Processes.parent_process_name Processes.parent_process_path Processes.process Processes.process_exec
 9   Processes.process_guid Processes.process_hash Processes.process_id Processes.process_integrity_level
10   Processes.process_name Processes.process_path Processes.user Processes.user_id Processes.vendor_product
11
12| `drop_dm_object_name(Processes)`
13
14| `security_content_ctime(firstTime)`
15
16| `security_content_ctime(lastTime)`
17
18| `windows_chromium_process_loaded_extension_via_command_line_filter`

Data Source

Name Platform Sourcetype Source
CrowdStrike ProcessRollup2 Other '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_process_loaded_extension_via_command_line_filter search *
windows_chromium_process_loaded_extension_via_command_line_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
T1185 Browser Session Hijacking Collection
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

Developers or IT admins loading unpacked extensions for testing or deployment purposes.

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message:

A $process_name$ process attempted to load an extension via the commandline $process$ on $dest$.

Risk Object Risk Object Type Risk Score Threat Objects
dest system 20 parent_process_name, process_name, process

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