Techniques
Sample rules
Attempt To Stop Security Service
- source: splunk
- technicques:
- T1562.001
- T1562
Description
The following analytic detects attempts to stop security-related services on an endpoint, which may indicate malicious activity. It leverages data from Endpoint Detection and Response (EDR) agents, specifically searching for processes involving the “sc.exe” command with the “stop” parameter. This activity is significant because disabling security services can undermine the organization’s security posture, potentially leading to unauthorized access, data exfiltration, or further attacks like malware installation or privilege escalation. If confirmed malicious, this behavior could compromise the endpoint and the entire network, necessitating immediate investigation and response.
Detection logic
| tstats `security_content_summariesonly` values(Processes.process) as process min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where `process_net` OR Processes.process_name = sc.exe Processes.process="* stop *" by Processes.dest Processes.user Processes.parent_process Processes.parent_process_name Processes.process_name Processes.original_file_name Processes.process Processes.process_id Processes.parent_process_id
| `drop_dm_object_name(Processes)`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
|lookup security_services_lookup service as process OUTPUTNEW category, description
| search category=security
| `attempt_to_stop_security_service_filter`
Windows SubInAcl Execution
- source: splunk
- technicques:
- T1222.001
Description
The following analytic detects the execution of the SubInAcl utility. SubInAcl is a legacy Windows Resource Kit tool from the Windows 2003 era, used to manipulate security descriptors of securable objects. It leverages data from Endpoint Detection and Response (EDR) agents, specifically searching for any process execution involving “SubInAcl.exe” binary. This activity can be significant because the utility should be rarely found on modern Windows machines, which mean any execution could potentially be considered suspicious. If confirmed malicious, this could allow an attacker to blind defenses by tampering with EventLog ACLs or modifying the access to a previously denied resource.
Detection logic
| tstats `security_content_summariesonly` values(Processes.process) as process min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where (Processes.process_name=subinacl.exe OR Processes.original_file_name=SubInAcl.exe) by Processes.dest Processes.user Processes.parent_process Processes.parent_process_name Processes.process_name Processes.original_file_name Processes.process Processes.process_id Processes.parent_process_id
| `drop_dm_object_name(Processes)`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `windows_subinacl_execution_filter`
Windows New Service Security Descriptor Set Via Sc.EXE
- source: splunk
- technicques:
- T1564
Description
The following analytic detects changes in a service security descriptor where a new deny ace has been added. It leverages data from Endpoint Detection and Response (EDR) agents, specifically searching for any process execution involving the “sc.exe” binary with the “sdset” flag targeting any service and adding a dedicated deny ace. If confirmed malicious, this could allow an attacker to escalate their privileges, blind defenses and more.
Detection logic
| tstats `security_content_summariesonly` values(Processes.process) as process min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where (Processes.process_name=sc.exe OR Processes.original_file_name=sc.exe) Processes.process="*sdset *" by Processes.dest Processes.user Processes.parent_process Processes.parent_process_name Processes.process_name Processes.original_file_name Processes.process Processes.process_id Processes.parent_process_id
| `drop_dm_object_name(Processes)`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `windows_new_service_security_descriptor_set_via_sc_exe_filter`