Name:Windows Impair Defense Override SmartScreen Prompt id:08058866-7987-486f-b042-275715ef6e9d 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 override the Windows Defender SmartScreen prompt. It leverages data from the Endpoint.Registry data model, specifically monitoring changes to the "PreventSmartScreenPromptOverride" registry setting. This activity is significant because it indicates an attempt to disable the prevention of user overrides for SmartScreen prompts, potentially allowing users to bypass security warnings. If confirmed malicious, this could lead to users inadvertently executing or accessing harmful content, increasing the risk of security incidents or system compromises. 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\\Edge\\PreventSmartScreenPromptOverride" 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_override_smartscreen_prompt_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:Windows Defender SmartScreen prompt was override 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
