Detection: Excessive Usage Of SC Service Utility

Description

The following analytic detects excessive usage of the sc.exe service utility on a host machine. It leverages Sysmon EventCode 1 logs to identify instances where sc.exe is executed more frequently than normal within a 15-minute window. This behavior is significant as it is commonly associated with ransomware, cryptocurrency miners, and other malware attempting to create, modify, delete, or disable services, potentially related to security applications or for privilege escalation. If confirmed malicious, this activity could allow attackers to manipulate critical services, leading to system compromise or disruption of security defenses.

Search

 1
 2| tstats `security_content_summariesonly` count as numScExe min(_time) as firstTime max(_time) as lastTime values(Processes.action) as action values(Processes.original_file_name) as original_file_name values(Processes.parent_process_exec) as parent_process_exec values(Processes.parent_process_guid) as parent_process_guid values(Processes.parent_process_name) as parent_process_name values(Processes.parent_process_path) as parent_process_path values(Processes.process) as process values(Processes.process_exec) as process_exec values(Processes.process_guid) as process_guid values(Processes.process_hash) as process_hash values(Processes.process_id) as process_id values(Processes.process_integrity_level) as process_integrity_level values(Processes.process_path) as process_path values(Processes.user_id) as user_id values(Processes.vendor_product) as vendor_product values(Processes.parent_process) as parent_process values(Processes.process_name) as process_name values(Processes.parent_process_id) as parent_process_id values(Processes.user) as user from datamodel=Endpoint.Processes where Processes.process_name = "sc.exe" by Processes.dest _time span=15m 
 3| `drop_dm_object_name(Processes)` 
 4| eventstats avg(numScExe) as avgScExe, stdev(numScExe) as stdScExe, count as numSlots by dest 
 5| eval upperThreshold=(avgScExe + stdScExe *3) 
 6| eval isOutlier=if(avgScExe > 5 and avgScExe >= upperThreshold, 1, 0) 
 7| search isOutlier=1 
 8| `security_content_ctime(firstTime)` 
 9| `security_content_ctime(lastTime)` 
10| `excessive_usage_of_sc_service_utility_filter`

Data Source

Name	Platform	Sourcetype	Source
Sysmon EventID 1	Windows	'xmlwineventlog'	'XmlWinEventLog:Microsoft-Windows-Sysmon/Operational'

Macros Used

Annotations

Default Configuration

This detection is configured by default in Splunk Enterprise Security to run with the following settings:

Implementation

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. Tune and filter known instances where renamed taskkill.exe may be used.

Known False Positives

excessive execution of sc.exe is quite suspicious since it can modify or execute app in high privilege permission.

Associated Analytic Story

• Azorult

• Crypto Stealer

• Ransomware

Risk Based Analytics (RBA)

Risk Message:

Excessive Usage Of SC Service Utility

References

• https://app.any.run/tasks/c0f98850-af65-4352-9746-fbebadee4f05/

Detection Testing

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: GitHub | Version: 7