Non Chrome Process Accessing Chrome Default Dir

Status: production
Severity: low
Group by: ObjectType, access_mask, dest, object_name, process_name, signature_id
Author: Teoderick Contreras, Splunk
Source: github.com/splunk/security_content

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.

Known false positives

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

MITRE ATT&CK coverage

Tactic	Techniques
Credential Access	`T1555.003` Credentials from Password Stores: Credentials from Web Browsers

Telemetry coverage

Provider	Record / event type
Security-Auditing	Event ID 4663: An attempt was made to access an object.

Rule body

name: Non Chrome Process Accessing Chrome Default Dir
id: 81263de4-160a-11ec-944f-acde48001122
version: 20
creation_date: '2021-09-15'
modification_date: '2026-06-25'
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: []
intermediate_findings:
    entities:
        - field: dest
          type: system
          score: 20
          message: a non chrome browser process $ProcessName$ accessing $ObjectName$
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
    - VIP Keylogger
    - Salat Stealer
    - Phantom Stealer
asset_type: Endpoint
mitre_attack_id:
    - T1555.003
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: endpoint
security_domain: endpoint

Stages and Predicates

Stage 1: `search`

`wineventlog_security` EventCode=4663 NOT (ProcessName IN ("*\\chrome.exe", "*\\explorer.exe", "*sql*", "*\\dllhost.exe")) ObjectName="*\\Google\\Chrome\\User Data\\Default*"

Stage 2: `stats`

| stats count min(_time) as firstTime max(_time) as lastTime by ObjectName ObjectType ProcessName AccessMask EventCode dest

Stage 3: `search`

| `security_content_ctime(firstTime)`

Stage 4: `search`

| `security_content_ctime(lastTime)`

Stage 5: `search`

| `non_chrome_process_accessing_chrome_default_dir_filter`

Exclusions

The rule actively suppresses these predicates.

Field	Kind	Excluded values	Search
`ProcessName`	in	`"\\chrome.exe"`, `"\\dllhost.exe"`, `"\\explorer.exe"`, `"sql*"`	`excludes:ProcessName`

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`EventCode`	eq	`4663` corpus 35 (splunk 30, kusto 5)	`field:"EventID" kind:eq value:"4663"`
`ObjectName`	eq	`"\\Google\\Chrome\\User Data\\Default"`	`field:"ObjectName" kind:eq`