splunk_escuAnomaly

Non Chrome Process Accessing Chrome Default Dir

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.

MITRE ATT&CK

T1555.003

Detection Query

`wineventlog_security` EventCode=4663 NOT (ProcessName IN ("*\\chrome.exe", "*\\explorer.exe", "*sql*", "*\\dllhost.exe")) 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`

Author

Teoderick Contreras, Splunk

Created

2026-03-10

Data Sources

Windows Event Log Security 4663

Tags

StealC StealerCISA AA23-347APhemedrone StealerDarkGate MalwareNjRATMalicious Inno Setup LoaderSalt TyphoonRemcosWarzone RATQuasar RAT3CX Supply Chain AttackAgentTeslaFIN7SnappyBeeRedLine StealerSnake KeyloggerChina-Nexus Threat ActivityLokibotBlankGrabber Stealer

Raw Content

name: Non Chrome Process Accessing Chrome Default Dir
id: 81263de4-160a-11ec-944f-acde48001122
version: 15
date: '2026-03-10'
author: Teoderick Contreras, Splunk
status: production
type: Anomaly
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.
data_source:
    - Windows Event Log Security 4663
search: '`wineventlog_security` EventCode=4663 NOT (ProcessName IN ("*\\chrome.exe", "*\\explorer.exe", "*sql*", "*\\dllhost.exe")) 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`'
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 chrome may catch by this rule.
references: []
drilldown_searches:
    - name: View the detection results for - "$dest$"
      search: '%original_detection_search% | search  dest = "$dest$"'
      earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
    - name: View risk events for the last 7 days for - "$dest$"
      search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$dest$") 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 non chrome browser process $ProcessName$ accessing $ObjectName$
    risk_objects:
        - field: dest
          type: system
          score: 20
    threat_objects: []
tags:
    analytic_story:
        - StealC Stealer
        - CISA AA23-347A
        - Phemedrone Stealer
        - DarkGate Malware
        - NjRAT
        - Malicious Inno Setup Loader
        - Salt Typhoon
        - Remcos
        - Warzone RAT
        - Quasar RAT
        - 3CX Supply Chain Attack
        - AgentTesla
        - FIN7
        - SnappyBee
        - RedLine Stealer
        - Snake Keylogger
        - China-Nexus Threat Activity
        - Lokibot
        - BlankGrabber Stealer
    asset_type: Endpoint
    mitre_attack_id:
        - T1555.003
    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/T1555/non_chrome_process_accessing_chrome_default_dir/windows-xml.log
          source: XmlWinEventLog:Security
          sourcetype: XmlWinEventLog