Windows New Service Security Descriptor Set Via Sc.EXE
Description
The following analytic detects changes in a service security descriptor. 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. This behavior can be legitimate, such as when a user or administrator is configuring a service's security settings. Investigate appropariate services to determine if the behavior is malicious. If confirmed malicious, this could allow an attacker to escalate their privileges, blind defenses and more.
Query · spl
| tstats `security_content_summariesonly`
count min(_time) as firstTime
max(_time) as lastTime
values(Processes.process) as process
FROM datamodel=Endpoint.Processes WHERE
(
Processes.process_name=sc.exe
OR
Processes.original_file_name=sc.exe
)
Processes.process="*sdset *"
BY Processes.action Processes.dest Processes.original_file_name
Processes.parent_process Processes.parent_process_exec
Processes.parent_process_guid Processes.parent_process_id
Processes.parent_process_name Processes.parent_process_path
Processes.process Processes.process_exec Processes.process_guid
Processes.process_hash Processes.process_id Processes.process_integrity_level
Processes.process_name Processes.process_path Processes.user
Processes.user_id Processes.vendor_product
| `drop_dm_object_name(Processes)`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `windows_new_service_security_descriptor_set_via_sc_exe_filter`
Implementation guide
The detection is based on data that originates from Endpoint Detection and Response (EDR) agents. These agents are designed to provide security-related telemetry from the endpoints where the agent is installed. To implement this search, you must ingest logs that contain the process name, and process original file name. Additionally, you must ingest complete command-line executions. These logs must be processed using the appropriate Splunk Technology Add-ons that are specific to the EDR product. The logs must also be mapped to the Processes node of the Endpoint data model. Use the Splunk Common Information Model (CIM) to normalize the field names and speed up the data modeling process.
Known false positives
- - False positives are expected from legitimate system administrator scripts or installation utilities. Filter known parent image and commandline combinations.
Analyst notes
Known false positives: - False positives are expected from legitimate system administrator scripts or installation utilities. Filter known parent image and commandline combinations.