Silenttrinity Stager Msbuild Activity

Hunt Hypothesis

Detects a possible remote connections to Silenttrinity c2

Detection Rule

Sigma (Original)

title: Silenttrinity Stager Msbuild Activity
id: 50e54b8d-ad73-43f8-96a1-5191685b17a4
status: test
description: Detects a possible remote connections to Silenttrinity c2
references:
    - https://www.blackhillsinfosec.com/my-first-joyride-with-silenttrinity/
author: Kiran kumar s, oscd.community
date: 2020-10-11
modified: 2022-10-05
tags:
    - attack.execution
    - attack.stealth
    - attack.t1127.001
logsource:
    category: network_connection
    product: windows
detection:
    selection:
        Image|endswith: '\msbuild.exe'
    filter:
        DestinationPort:
            - 80
            - 443
        Initiated: 'true'
    condition: selection and filter
falsepositives:
    - Unknown
level: high

KQL (Azure Sentinel)

imNetworkSession
| where (SrcProcessName endswith "\\msbuild.exe" or DstProcessName endswith "\\msbuild.exe") and ((DstPortNumber in~ ("80", "443")) and NetworkDirection =~ "true")

Required Data Sources

False Positive Guidance

• Unknown

MITRE ATT&CK Context

• Tactic: Execution
• Technique: T1127.001 — T1127.001

References

• https://www.blackhillsinfosec.com/my-first-joyride-with-silenttrinity/
• SigmaHQ Rule