Name:Windows Impair Defenses Disable HVCI id:b061dfcc-f0aa-42cc-a6d4-a87f172acb79 version:3 date:2024-09-30 author:Michael Haag, Splunk status:production type:TTP Description:The following analytic detects the disabling of Hypervisor-protected Code Integrity (HVCI) by monitoring changes in the Windows registry. It leverages data from the Endpoint datamodel, specifically focusing on registry paths and values related to HVCI settings. This activity is significant because HVCI helps protect the kernel and system processes from tampering by malicious code. If confirmed malicious, disabling HVCI could allow attackers to execute unsigned kernel-mode code, potentially leading to kernel-level rootkits or other severe security breaches. 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 = "*\\CurrentControlSet\\Control\\DeviceGuard\\Scenarios\\HypervisorEnforcedCodeIntegrity\\Enabled" Registry.registry_value_data="0x00000000" by Registry.registry_path Registry.registry_value_name Registry.registry_value_data Registry.process_guid Registry.action Registry.user Registry.dest | `drop_dm_object_name(Registry)` | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `windows_impair_defenses_disable_hvci_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. In addition, confirm the latest CIM App 4.20 or higher is installed and the latest TA for the endpoint product. known_false_positives:False positives will be limited to administrative scripts disabling HVCI. Filter as needed. References: -https://www.microsoft.com/en-us/security/blog/2023/04/11/guidance-for-investigating-attacks-using-cve-2022-21894-the-blacklotus-campaign/ 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: - 'BlackLotus Campaign' - 'Windows Defense Evasion Tactics' - 'Windows Registry Abuse' asset_type:Endpoint atomic_guid: - '70bd71e6-eba4-4e00-92f7-617911dbe020' confidence:100 impact:70 message:HVCI has been disabled on $dest$. mitre_attack_id: - 'T1562.001' - 'T1562' observable: name:'dest' type:'Endpoint' - role: - 'Victim' product: - 'Splunk Enterprise' - 'Splunk Enterprise Security' - 'Splunk Cloud' required_fields: - 'Registry.registry_path' - 'Registry.registry_value_data' - 'Registry.registry_value_name' - 'Registry.process_guid' - 'Registry.action' - 'Registry.user' - 'Registry.dest' risk_score:70 security_domain:endpoint
