Name:Windows Modify Registry Suppress Win Defender Notif id:e3b42daf-fff4-429d-bec8-2a199468cea9 version:7 date:2025-04-22 author:Teoderick Contreras, Splunk status:production type:Anomaly Description:The following analytic detects modifications in the Windows registry to suppress Windows Defender notifications. It leverages data from the Endpoint.Registry datamodel, specifically targeting changes to the "Notification_Suppress" registry value. This activity is significant because adversaries, including those deploying Azorult malware, use this technique to bypass Windows Defender and disable critical notifications. If confirmed malicious, this behavior could allow attackers to evade detection, maintain persistence, and execute further malicious activities without alerting the user or security tools. 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= "*\\Windows Defender\\UX Configuration\\Notification_Suppress*" Registry.registry_value_data="0x00000001" 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_modify_registry_suppress_win_defender_notif_filter`
how_to_implement:To successfully implement this search you need to be ingesting information on process that include the name of the process responsible for the changes from your endpoints into the `Endpoint` datamodel in the `Registry` node. Also make sure that this registry was included in your config files ex. sysmon config to be monitored. known_false_positives:administrators may enable or disable this feature that may cause some false positive. References: -https://docs.microsoft.com/en-us/windows-hardware/customize/desktop/unattend/microsoft-windows-remoteassistance-exe-fallowtogethelp -https://app.any.run/tasks/a6f2ffe2-e6e2-4396-ae2e-04ea0143f2d8/ 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:'$info_max_time$' tags: analytic_story: - 'Azorult' - 'CISA AA23-347A' asset_type:Endpoint mitre_attack_id: - 'T1112' product: - 'Splunk Enterprise' - 'Splunk Enterprise Security' - 'Splunk Cloud' security_domain:endpoint
