Detection: Windows Service Create SliverC2

Updated Date: 2024-05-25 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.

Search

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	Supported App
Windows Event Log System 7045	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_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

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 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

BishopFox Sliver Adversary Emulation Framework

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: 2