Windows Query Registry Browser List Application

SPLUNK detection rule by Teoderick Contreras, Splunk · Apache-2.0

The following analytic detects a suspicious process accessing the registry entries for default internet browsers. It leverages Windows Security Event logs, specifically event code 4663, to identify access attempts to these registry paths. This activity is significant because adversaries can exploit this registry key to gather information about installed browsers and their settings, potentially leading to the theft of sensitive data such as login credentials and browsing history. If confirmed malicious, this behavior could enable attackers to exfiltrate sensitive information and compromise user accounts.

name: Windows Query Registry Browser List Application
id: 45ebd21c-f4bf-4ced-bd49-d25b6526cebb
version: 10
creation_date: '2023-05-02'
modification_date: '2026-05-13'
author: Teoderick Contreras, Splunk
status: production
type: Anomaly
description: The following analytic detects a suspicious process accessing the registry entries for default internet browsers. It leverages Windows Security Event logs, specifically event code 4663, to identify access attempts to these registry paths. This activity is significant because adversaries can exploit this registry key to gather information about installed browsers and their settings, potentially leading to the theft of sensitive data such as login credentials and browsing history. If confirmed malicious, this behavior could enable attackers to exfiltrate sensitive information and compromise user accounts.
data_source:
    - Windows Event Log Security 4663
search: '`wineventlog_security` EventCode=4663 object_file_path IN ("*\\SOFTWARE\\Clients\\StartMenuInternet\\*", "*\\SOFTWARE\\Clients\\StartMenuInternet\\*") AND NOT process_path IN ("*:\\Windows\\System32\\*", "*:\\Windows\\SysWow64\\*", *:\\Windows\\WinSxS\\*, "*:\\Program Files\\*", "*:\\Program Files (x86)\\*") | stats count min(_time) as firstTime max(_time) as lastTime by object_file_name object_file_path process_name process_path  process_id EventCode dest | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `windows_query_registry_browser_list_application_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: uninstall application may access this registry to remove the entry of the target application. filter is needed.
references:
    - https://malpedia.caad.fkie.fraunhofer.de/details/win.redline_stealer
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 ("$dest$") | 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: 7d
      latest_offset: "0"
intermediate_findings:
    entities:
        - field: dest
          type: system
          score: 20
          message: A suspicious process accessing installed default browser registry on $dest$
analytic_story:
    - China-Nexus Threat Activity
    - SnappyBee
    - RedLine Stealer
    - Salt Typhoon
asset_type: Endpoint
mitre_attack_id:
    - T1012
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: endpoint
security_domain: endpoint
tests:
    - name: True Positive Test
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/malware/redline/browser_list/ar3_4663_redline_reg.log
          source: XmlWinEventLog:Security
          sourcetype: XmlWinEventLog
      test_type: unit

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7a3c7747-a64a-49a8-a06a-183252b72eca

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