diff --git a/detections/endpoint/disable_amsi_through_registry.yml b/detections/endpoint/disable_amsi_through_registry.yml index 194fada226..c565d442b8 100644 --- a/detections/endpoint/disable_amsi_through_registry.yml +++ b/detections/endpoint/disable_amsi_through_registry.yml @@ -6,20 +6,22 @@ author: Teoderick Contreras, Splunk type: batch datamodel: - Endpoint -description: this search is to identify modification in registry to disable AMSI windows feature to evade detections. - This technique was seen in several ransomware, RAT and even APT to impaire defenses of the compromise machine and to - be able to execute payload with minimal alert as much as possible. +description: this search is to identify modification in registry to disable AMSI windows + feature to evade detections. This technique was seen in several ransomware, RAT + and even APT to impaire defenses of the compromise machine and to be able to execute + payload with minimal alert as much as possible. search: '| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) - as lastTime from datamodel=Endpoint.Registry where Registry.registry_path= "*\\SOFTWARE\\Microsoft\\Windows Script\\Settings\\AmsiEnable" - Registry.registry_value_name = "DWORD (0x00000000)" by Registry.registry_path Registry.registry_key_name - Registry.registry_value_name Registry.dest | `drop_dm_object_name(Registry)` | `security_content_ctime(firstTime)` - |`security_content_ctime(lastTime)` - | `disable_amsi_through_registry_filter`' + as lastTime from datamodel=Endpoint.Registry where Registry.registry_path= "*\\SOFTWARE\\Microsoft\\Windows + Script\\Settings\\AmsiEnable" Registry.registry_value_name = "DWORD (0x00000000)" + by Registry.registry_path Registry.registry_key_name Registry.registry_value_name + Registry.dest | `drop_dm_object_name(Registry)` | `security_content_ctime(firstTime)` + |`security_content_ctime(lastTime)` | `disable_amsi_through_registry_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: network operator may disable this feature of windows but not so common. +known_false_positives: network operator may disable this feature of windows but not + so common. references: - https://blog.f-secure.com/hunting-for-amsi-bypasses/ - https://gist.github.com/rxwx/8955e5abf18dc258fd6b43a3a7f4dbf9 @@ -41,4 +43,7 @@ tags: - Registry.user - Registry.dest - Registry.registry_value_name - security_domain: endpoint \ No newline at end of file + security_domain: endpoint + automated_detection_testing: passed + dataset: + - https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/malware/ransomware_ttp/data2/windows-sysmon.log