LoFP LoFP / this windows feature may implement by administrator in some server where shutdown is critical. in that scenario filter of machine and users that can modify this registry is needed.

Techniques

Sample rules

Windows Disable LogOff Button Through Registry

Description

This analytic is to detect a suspicious registry modification to disable logoff feature in windows host. This registry when enable will prevent users to log off of the system by using any method, including programs run from the command line, such as scripts. It also disables or removes all menu items and buttons that log the user off of the system. This technique was seen abused by ransomware malware to make the compromised host un-useful and hard to remove other registry modification made on the machine that needs restart to take effect. This windows feature may implement by administrator in some server where shutdown is critical. In that scenario filter of machine and users that can modify this registry is needed.

Detection logic


| tstats `security_content_summariesonly` count FROM datamodel=Endpoint.Registry WHERE (Registry.registry_path= "*\\SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Policies\\Explorer\\*" Registry.registry_value_name IN ("NoLogOff", "StartMenuLogOff") Registry.registry_value_data = "0x00000001") BY _time span=1h 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)` 
| `windows_disable_logoff_button_through_registry_filter`

Windows Disable Shutdown Button Through Registry

Description

This analytic is to detect a suspicious registry modification to disable shutdown button on the logon user. This technique was seen in several malware especially in ransomware family like killdisk malware variant to make the compromised host un-useful and hard to remove other registry modification made on the machine that needs restart to take effect. This windows feature may implement by administrator in some server where shutdown is critical. In that scenario filter of machine and users that can modify this registry is needed.

Detection logic


| tstats `security_content_summariesonly` count FROM datamodel=Endpoint.Registry WHERE ((Registry.registry_path= "*\\SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Policies\\System\\shutdownwithoutlogon" Registry.registry_value_data = "0x00000000") OR (Registry.registry_path="*\\SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Policies\\Explorer\\NoClose" Registry.registry_value_data = "0x00000001")) BY _time span=1h 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)` 
| `windows_disable_shutdown_button_through_registry_filter`