Windows Disable Shutdown Button Through Registry
Description
The following analytic detects suspicious registry modifications that disable the shutdown button on a user's logon screen. It leverages data from the Endpoint.Registry data model, specifically monitoring changes to registry paths associated with shutdown policies. This activity is significant because it is a tactic used by malware, particularly ransomware like KillDisk, to hinder system usability and prevent the removal of malicious changes. If confirmed malicious, this could impede system recovery efforts, making it difficult to restart the machine and remove other harmful modifications.
Query · spl
| tstats `security_content_summariesonly`
count min(_time) as firstTime
max(_time) as lastTime
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 Registry.action Registry.dest Registry.process_guid Registry.process_id
Registry.registry_hive Registry.registry_path Registry.registry_key_name
Registry.registry_value_data Registry.registry_value_name
Registry.registry_value_type Registry.status
Registry.user Registry.vendor_product
| `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`
Implementation guide
To successfully implement this search, you need to be ingesting logs with the registry value name, registry path, and registry value data from your endpoints. If you are using Sysmon, you must have at least version 2.0 of the official Sysmon TA. https://splunkbase.splunk.com/app/5709
Known false positives
- This Windows feature may be implemented by an administrator on some servers where shutdown is restricted. In that scenario, filtering by the machines and users allowed to modify this registry key is recommended.
Analyst notes
Known false positives: This Windows feature may be implemented by an administrator on some servers where shutdown is restricted. In that scenario, filtering by the machines and users allowed to modify this registry key is recommended.