Detection: Windows Service Created with Suspicious Service Path

Updated Date: 2024-05-21 ID: 429141be-8311-11eb-adb6-acde48001122 Author: Teoderick Contreras, Mauricio Velazco, Splunk Type: TTP Product: Splunk Enterprise Security

Description

The following analytic detects the creation of a Windows Service with a binary path located in uncommon directories, using Windows Event ID 7045. It leverages logs from the wineventlog_system to identify services installed outside typical system directories. This activity is significant as adversaries, including those deploying Clop ransomware, often create malicious services for lateral movement, remote code execution, persistence, and execution. If confirmed malicious, this could allow attackers to maintain persistence, execute arbitrary code, and potentially escalate privileges, posing a severe threat to the environment.

1 `wineventlog_system` EventCode=7045 ImagePath = "*.exe" NOT (ImagePath IN ("*:\\Windows\\*", "*:\\Program File*", "*:\\Programdata\\*", "*%systemroot%\\*")) 
2| stats count min(_time) as firstTime max(_time) as lastTime by EventCode ImagePath ServiceName ServiceType StartType Computer UserID 
3| rename Computer as dest
4| `security_content_ctime(firstTime)` 
5| `security_content_ctime(lastTime)` 
6| `windows_service_created_with_suspicious_service_path_filter`

Data Source

Name Platform Sourcetype Source Supported App
Windows Event Log System 7045 Windows icon Windows 'xmlwineventlog' 'XmlWinEventLog:System' N/A

Macros Used

Name Value
security_content_ctime convert timeformat="%Y-%m-%dT%H:%M:%S" ctime($field$)
windows_service_created_with_suspicious_service_path_filter search *
windows_service_created_with_suspicious_service_path_filter is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Annotations

- MITRE ATT&CK
+ Kill Chain Phases
+ NIST
+ CIS
- Threat Actors
ID Technique Tactic
T1569 System Services Execution
T1569.002 Service Execution Execution
KillChainPhase.INSTALLATION
NistCategory.DE_CM
Cis18Value.CIS_10
TeamTNT
APT32
APT38
APT39
APT41
Blue Mockingbird
Chimera
FIN6
Ke3chang
Silence
Wizard Spider

Default Configuration

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

Setting Value
Disabled true
Cron Schedule 0 * * * *
Earliest Time -70m@m
Latest Time -10m@m
Schedule Window auto
Creates Notable Yes
Rule Title %name%
Rule Description %description%
Notable Event Fields user, dest
Creates Risk Event True
This configuration file applies to all detections of type TTP. These detections will use Risk Based Alerting and generate Notable Events.

Implementation

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

Risk Based Analytics (RBA)

Risk Message Risk Score Impact Confidence
A service $ImagePath$ was created from a non-standard path using $ServiceName$ on $dest$ 56 70 80
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

References

Detection Testing

Test Type Status Dataset Source Sourcetype
Validation ✅ Passing N/A N/A N/A
Unit ✅ Passing Dataset XmlWinEventLog:System XmlWinEventLog
Integration ✅ Passing Dataset XmlWinEventLog:System XmlWinEventLog

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: 5