Detection: Windows Service Create SliverC2

Updated Date: 2024-09-30 ID: 89dad3ee-57ec-43dc-9044-131c4edd663f Author: Michael Haag, Splunk Type: TTP Product: Splunk Enterprise Security

Description

The following analytic detects the creation of a Windows service named "Sliver" with the description "Sliver Implant," indicative of SliverC2 lateral movement using the PsExec module. It leverages Windows EventCode 7045 from the System Event log to identify this activity. This behavior is significant as it may indicate an adversary's attempt to establish persistence or execute commands remotely. If confirmed malicious, this activity could allow attackers to maintain control over the compromised system, execute arbitrary code, and further infiltrate the network.

1`wineventlog_system` EventCode=7045 ServiceName="sliver" 
2| stats count min(_time) as firstTime max(_time) as lastTime by Computer EventCode ImagePath ServiceName ServiceType 
3| rename Computer as dest 
4| `security_content_ctime(firstTime)` 
5| `security_content_ctime(lastTime)` 
6| `windows_service_create_sliverc2_filter`

Data Source

Name Platform Sourcetype Source
Windows Event Log System 7045 Windows icon Windows 'xmlwineventlog' 'XmlWinEventLog:System'

Macros Used

Name Value
security_content_ctime convert timeformat="%Y-%m-%dT%H:%M:%S" ctime($field$)
windows_service_create_sliverc2_filter search *
windows_service_create_sliverc2_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
INC Ransom
Ke3chang
Moonstone Sleet
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 implement this analytic, the Windows EventCode 7045 will need to be logged from the System Event log. The Windows TA for Splunk is also recommended.

Known False Positives

False positives should be limited, but if another service out there is named Sliver, filtering may be needed.

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message Risk Score Impact Confidence
A user mode service was created on $dest$ related to SliverC2. 90 90 100
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: 3