Randomly Generated Windows Service Name

Original Source: [splunk source]
Name:Randomly Generated Windows Service Name
id:2032a95a-5165-11ec-a2c3-3e22fbd008af
version:5
date:2024-10-17
author:Mauricio Velazco, Splunk
status:experimental
type:Hunting
Description:The following analytic detects the installation of a Windows Service with a suspicious, high-entropy name, indicating potential malicious activity. It leverages Event ID 7045 and the `ut_shannon` function from the URL ToolBox Splunk application to identify services with random names. This behavior is significant as adversaries often use randomly named services for lateral movement and remote code execution. If confirmed malicious, this activity could allow attackers to execute arbitrary code, escalate privileges, or maintain persistence within the environment.
Data_source:
  • -Windows Event Log System 7045
search:`wineventlog_system` EventCode=7045
| lookup ut_shannon_lookup word as Service_Name
| where ut_shannon > 3
| table EventCode ComputerName Service_Name ut_shannon Service_Start_Type Service_Type Service_File_Name
| `randomly_generated_windows_service_name_filter`


how_to_implement:To successfully implement this search, you need to be ingesting logs with the Service name, Service File Name Service Start type, and Service Type from your endpoints. The Windows TA as well as the URL ToolBox application are also required.
known_false_positives:Legitimate applications may use random Windows Service names.
References:
  -https://attack.mitre.org/techniques/T1543/003/
drilldown_searches:
  :
tags:
  analytic_story:
    - 'Active Directory Lateral Movement'
    - 'BlackSuit Ransomware'
  asset_type:Endpoint
  confidence:50
  impact:90
  message:A Windows Service with a suspicious service name was installed on $ComputerName$
  mitre_attack_id:
    - 'T1543'
    - 'T1543.003'
  observable:
    name:'ComputerName'
    type:'Endpoint'
    - role:
      - 'Victim'
  product:
    - 'Splunk Enterprise'
    - 'Splunk Enterprise Security'
    - 'Splunk Cloud'
  required_fields:
    - '_time'
    - 'EventCode'
    - 'ComputerName'
    - 'Service_File_Name'
    - 'Service_Type'
    - 'Service_Name'
    - 'Service_Start_Type'
  risk_score:45
  security_domain:endpoint

tests:
  :
manual_test:None