Name:Windows Chrome Extension Allowed Registry Modification id:2846089a-ffe9-4881-a2a2-43f3be2b8cc7 version:4 date:None author:Teoderick Contreras, Splunk status:production type:Anomaly Description:The following analytic detects modifications to the Windows registry keys that control the Chrome Extension Install Allowlist. Unauthorized changes to these keys may indicate attempts to bypass Chrome extension restrictions or install unapproved extensions. This detection helps identify potential security policy violations or malicious activity targeting Chrome extension settings. Data_source:
-Sysmon EventID 13
search:| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Registry where Registry.registry_path = "*\\Google\\Chrome\\ExtensionInstallAllowlist*" by Registry.action Registry.dest Registry.process_guid Registry.process_id Registry.registry_hive Registry.registry_path Registry.registry_key_name Registry.registry_value_data Registry.registry_value_name Registry.registry_value_type Registry.status Registry.user Registry.vendor_product | `drop_dm_object_name(Registry)` | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `windows_chrome_extension_allowed_registry_modification_filter`
how_to_implement:To successfully implement this search, you need to be ingesting logs with the registry value name, registry path, and registry value data from your endpoints. If you are using Sysmon, you must have at least version 2.0 of the official Sysmon TA. https://splunkbase.splunk.com/app/5709 known_false_positives:Legitimate IT admin updates to Chrome extension allowlist via Group Policy or enterprise management tools. Filtering is needed. References: -https://www.gdatasoftware.com/blog/2025/11/38298-learning-about-browser-hijacking 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' analytic_story:['Browser Hijacking']
