Name:Windows Impair Defense Configure App Install Control id:c54b7439-cfb1-44c3-bb35-b0409553077c version:4 date:2024-11-14 author:Teoderick Contreras, Splunk status:production type:TTP Description:The following analytic detects modifications to the Windows registry that disable the Windows Defender SmartScreen App Install Control feature. It leverages data from the Endpoint.Registry data model to identify changes to specific registry values. This activity is significant because disabling App Install Control can allow users to install potentially malicious web-based applications without restrictions, increasing the risk of security vulnerabilities. If confirmed malicious, this action could lead to the installation of harmful applications, potentially compromising the system and exposing sensitive information. 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= "*\\Microsoft\\Windows Defender\\SmartScreen\\ConfigureAppInstallControl" Registry.registry_value_data= "Anywhere") OR (Registry.registry_path= "*\\Microsoft\\Windows Defender\\SmartScreen\\ConfigureAppInstallControlEnabled" Registry.registry_value_data= "0x00000000") 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)` | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `windows_impair_defense_configure_app_install_control_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. known_false_positives:It is unusual to turn this feature off a Windows system since it is a default security control, although it is not rare for some policies to disable it. Although no false positives have been identified, use the provided filter macro to tune the search. References: -https://x.com/malmoeb/status/1742604217989415386?s=20 -https://github.com/undergroundwires/privacy.sexy 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: - 'Windows Defense Evasion Tactics' - 'Windows Registry Abuse' asset_type:Endpoint confidence:70 impact:70 message:Define Windows Defender App Install Control registry set to disable on $dest$. mitre_attack_id: - 'T1562.001' - 'T1562' observable: name:'dest' type:'Endpoint' - role: - 'Victim' product: - 'Splunk Enterprise' - 'Splunk Enterprise Security' - 'Splunk Cloud' risk_score:49 required_fields: - '_time' - 'Registry.registry_key_name' - 'Registry.registry_value_name' - 'Registry.dest' - 'Registry.user' - 'Registry.registry_path' - 'Registry.action' security_domain:endpoint
