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Description

The following analytic detects a non-Chrome process accessing files in the Chrome user default folder. It leverages Windows Security Event logs, specifically event code 4663, to identify unauthorized access attempts. This activity is significant because the Chrome default folder contains sensitive user data such as login credentials, browsing history, and cookies. If confirmed malicious, this behavior could indicate an attempt to exfiltrate sensitive information, often associated with RATs, trojans, and advanced persistent threats like FIN7. Such access could lead to data theft and further compromise of the affected system.

  • Type: Anomaly

  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud

  • Last Updated: 2024-05-25
  • Author: Teoderick Contreras, Splunk
  • ID: 81263de4-160a-11ec-944f-acde48001122

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1555 Credentials from Password Stores Credential Access
T1555.003 Credentials from Web Browsers Credential Access
Kill Chain Phase
  • Exploitation
NIST
  • DE.AE
CIS20
  • CIS 10
CVE 


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`wineventlog_security` EventCode=4663 NOT (ProcessName IN ("*\\chrome.exe", "*\\explorer.exe", "*sql*")) ObjectName="*\\Google\\Chrome\\User Data\\Default*" 
| stats count min(_time) as firstTime max(_time) as lastTime by ObjectName ObjectType ProcessName AccessMask EventCode dest 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `non_chrome_process_accessing_chrome_default_dir_filter`

Macros

The SPL above uses the following Macros:

:information_source: non_chrome_process_accessing_chrome_default_dir_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Required fields

List of fields required to use this analytic.

  • _time
  • Object_Name
  • Object_Type
  • process_name
  • Access_Mask
  • Accesses
  • process_id
  • EventCode
  • dest
  • user

How To Implement

To successfully implement this search, you must ingest Windows Security Event logs and track event code 4663. For 4663, enable "Audit Object Access" in Group Policy. Then check the two boxes listed for both "Success" and "Failure."

Known False Positives

other browser not listed related to firefox may catch by this rule.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
35.0 50 70 a non chrome browser process $ProcessName$ accessing $ObjectName$

:information_source: The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

Reference

Test Dataset

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 | version: 3