Name:Disabling Defender Services id:911eacdc-317f-11ec-ad30-acde48001122 version:8 date:2024-12-08 author:Teoderick Contreras, Splunk, Steven Dick status:production type:TTP Description:The following analytic detects the disabling of Windows Defender services by monitoring registry modifications. It leverages registry event data to identify changes to specific registry paths associated with Defender services, where the 'Start' value is set to '0x00000004'. This activity is significant because disabling Defender services can indicate an attempt by an adversary to evade detection and maintain persistence on the endpoint. If confirmed malicious, this action could allow attackers to execute further malicious activities undetected, leading to potential data breaches or system compromise. Data_source:
-Sysmon EventID 12
-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 = "*\\System\\CurrentControlSet\\Services\\*" AND (Registry.registry_path IN("*WdBoot*", "*WdFilter*", "*WdNisDrv*", "*WdNisSvc*","*WinDefend*", "*SecurityHealthService*")) AND Registry.registry_value_name = Start Registry.registry_value_data = 0x00000004) BY Registry.dest Registry.user Registry.registry_path Registry.registry_key_name Registry.registry_value_name Registry.registry_value_data Registry.process_guid | `drop_dm_object_name(Registry)`| where isnotnull(registry_value_data) | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `disabling_defender_services_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:admin or user may choose to disable windows defender product References: -https://thedfirreport.com/2021/10/18/icedid-to-xinglocker-ransomware-in-24-hours/ drilldown_searches: name:'View the detection results for - "$dest$" and "$user$"' search:'%original_detection_search% | search dest = "$dest$" user = "$user$"' earliest_offset:'$info_min_time$' latest_offset:'$info_max_time$' name:'View risk events for the last 7 days for - "$dest$" and "$user$"' search:'| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$dest$", "$user$") 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: - 'IcedID' - 'Windows Registry Abuse' - 'RedLine Stealer' asset_type:Endpoint confidence:70 impact:70 message:modified/added/deleted registry entry $registry_path$ in $dest$ mitre_attack_id: - 'T1562.001' - 'T1562' observable: name:'dest' type:'Hostname' - role: - 'Victim' name:'user' type:'User' - role: - 'Victim' product: - 'Splunk Enterprise' - 'Splunk Enterprise Security' - 'Splunk Cloud' required_fields: - '_time' - 'Registry.dest' - 'Registry.registry_value_name' - 'Registry.registry_key_name' - 'Registry.registry_path' - 'Registry.registry_value_data' - 'Registry.process_guid' risk_score:49 security_domain:endpoint
