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Description

The following analytic identifies Windows Service Control, sc.exe, attempting to delete a service. This is typically identified in parallel with other instances of service enumeration of attempts to stop a service and then delete it. Adversaries utilize this technique to terminate security services or other related services to continue there objective and evade detections.

  • Type: TTP
  • Product: Splunk Behavioral Analytics
  • Datamodel: Endpoint_Processes
  • Last Updated: 2021-11-24
  • Author: Teoderick Contreras, splunk
  • ID: a0c8c292-d01a-11eb-aa18-acde48001122

ATT&CK

ID Technique Tactic
T1489 Service Stop Impact
T1543 Create or Modify System Process Persistence, Privilege Escalation
T1543.003 Windows Service Persistence, Privilege Escalation 
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| from read_ssa_enriched_events() 
| eval timestamp=parse_long(ucast(map_get(input_event, "_time"), "string", null)), cmd_line=lower(ucast(map_get(input_event, "process"), "string", null)), process_name=lower(ucast(map_get(input_event, "process_name"), "string", null)), process_path=ucast(map_get(input_event, "process_path"), "string", null), parent_process_name=ucast(map_get(input_event, "parent_process_name"), "string", null), event_id=ucast(map_get(input_event, "event_id"), "string", null) 
| where cmd_line IS NOT NULL AND like(cmd_line, "%delete%") AND process_name = "sc.exe" 
| eval start_time=timestamp, end_time=timestamp, entities=mvappend(ucast(map_get(input_event, "dest_user_id"), "string", null), ucast(map_get(input_event, "dest_device_id"), "string", null)), body=create_map(["event_id", event_id, "cmd_line", cmd_line, "process_name", process_name, "parent_process_name", parent_process_name, "process_path", process_path]) 
| into write_ssa_detected_events();

Macros

The SPL above uses the following Macros:

Note that attempt_to_delete_services_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Required field

  • _time
  • dest_device_id
  • process_name
  • parent_process_name
  • process_path
  • dest_user_id
  • process
  • cmd_line

How To Implement

To successfully implement this search, you need to be ingesting logs with the process name, parent process, and command-line executions from your endpoints. If you are using Sysmon, you must have at least version 6.0.4 of the Sysmon TA.

Known False Positives

It is possible administrative scripts may start/stop/delete services. Filter as needed.

Associated Analytic story

Kill Chain Phase

  • Exploitation

RBA

Risk Score Impact Confidence Message
36.0 60 60 An instance of $parent_process_name$ spawning $process_name$ was identified on endpoint $dest_device_id$ by user $dest_user_id$ attempting to delete a service.

Note that risk score is calculated base on the following formula: (Impact * Confidence)/100

Reference

Test Dataset

Replay any dataset to Splunk Enterprise by using our replay.py tool or the UI. Alternatively you can replay a dataset into a Splunk Attack Range

source | version: 3