Windows Service Created Within Public Path

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Description

The following analytc uses Windows Event Id 7045, New Service Was Installed, to identify the creation of a Windows Service where the service binary path is located in public paths. This behavior could represent the installation of a malicious service. Red Teams and adversaries alike may create malicious Services for lateral movement or remote code execution

• Type: TTP

• Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud

• Last Updated: 2021-11-22
• Author: Mauricio Velazco, Splunk
• ID: 3abb2eda-4bb8-11ec-9ae4-3e22fbd008af

Annotations

ATT&CK

ATT&CK

ID	Technique	Tactic
T1543	Create or Modify System Process	Persistence, Privilege Escalation

T1543.003

Windows Service

Persistence, Privilege Escalation

Kill Chain Phase

• Installation
• Exploitation

NIST

• DE.CM

CIS20

• CIS 10

CVE

Search

`wineventlog_system` EventCode=7045  Service_File_Name = "*\.exe" NOT (Service_File_Name IN ("C:\\Windows\\*", "C:\\Program File*", "C:\\Programdata\\*", "%systemroot%\\*")) 
| stats count min(_time) as firstTime max(_time) as lastTime by ComputerName EventCode Service_File_Name Service_Name Service_Start_Type Service_Type 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `windows_service_created_within_public_path_filter`

Macros

The SPL above uses the following Macros:

• security_content_ctime
• wineventlog_system

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

Required fields

List of fields required to use this analytic.

• EventCode
• Service_File_Name
• Service_Type
• _time
• Service_Name
• Service_Start_Type

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.

Known False Positives

Legitimate applications may install services with uncommon services paths.

Associated Analytic Story

• Active Directory Lateral Movement
• Snake Malware

RBA

Risk Score	Impact	Confidence	Message
54.0	90	60	A Windows Service $Service_File_Name$ with a public path was created on $ComputerName

The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

Reference

• https://docs.microsoft.com/en-us/windows/win32/services/service-control-manager
• https://pentestlab.blog/2020/07/21/lateral-movement-services/

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

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