Techniques
Sample rules
Windows Registry Delete Task SD
- source: splunk
- technicques:
- T1053.005
- T1562
Description
The following analytic identifies a process attempting to delete a scheduled task SD (Security Descriptor) from within the registry path of that task. This may occur from a non-standard process running and may not come from reg.exe. This particular behavior will remove the actual Task Name from the Task Scheduler GUI and from the command-line query - schtasks.exe /query. In addition, in order to perform this action, the user context will need to be SYSTEM. Identifying the deletion of a scheduled task’s Security Descriptor from the registry is significant for a SOC as it may indicate malicious activity attempting to remove evidence of a scheduled task, potentially for defense evasion purposes. If a true positive is detected, it suggests an attacker with privileged access attempting to remove traces of their activities, which can have a significant impact on the security and functionality of affected systems. Immediate investigation and response are required to mitigate further risks and preserve the integrity of the environment.
Detection logic
| tstats `security_content_summariesonly` count from datamodel=Endpoint.Registry where Registry.registry_path IN ("*\\Schedule\\TaskCache\\Tree\\*") Registry.user="SYSTEM" Registry.registry_value_name="SD" (Registry.action=Deleted OR Registry.action=modified) by _time Registry.dest Registry.process_guid Registry.user Registry.registry_path Registry.registry_value_name Registry.registry_key_name Registry.registry_value_data Registry.status Registry.action
| `drop_dm_object_name(Registry)`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `windows_registry_delete_task_sd_filter`