Terminal Service Process Spawn

Hunt Hypothesis

Detects a process spawned by the terminal service server process (this could be an indicator for an exploitation of CVE-2019-0708)

Detection Rule

Sigma (Original)

title: Terminal Service Process Spawn
id: 1012f107-b8f1-4271-af30-5aed2de89b39
status: test
description: Detects a process spawned by the terminal service server process (this could be an indicator for an exploitation of CVE-2019-0708)
references:
    - https://securingtomorrow.mcafee.com/other-blogs/mcafee-labs/rdp-stands-for-really-do-patch-understanding-the-wormable-rdp-vulnerability-cve-2019-0708/
author: Florian Roth (Nextron Systems)
date: 2019-05-22
modified: 2023-01-25
tags:
    - attack.initial-access
    - attack.t1190
    - attack.lateral-movement
    - attack.t1210
    - car.2013-07-002
logsource:
    product: windows
    category: process_creation
detection:
    selection:
        ParentCommandLine|contains|all:
            - '\svchost.exe'
            - 'termsvcs'
    filter_img:
        Image|endswith:
            - '\rdpclip.exe'
            - ':\Windows\System32\csrss.exe'
            - ':\Windows\System32\wininit.exe'
            - ':\Windows\System32\winlogon.exe'
    filter_null:
        Image: null
    condition: selection and not 1 of filter_*
falsepositives:
    - Unknown
level: high

KQL (Azure Sentinel)

imProcessCreate
| where (ActingProcessCommandLine contains "\\svchost.exe" and ActingProcessCommandLine contains "termsvcs") and (not(((TargetProcessName endswith "\\rdpclip.exe" or TargetProcessName endswith ":\\Windows\\System32\\csrss.exe" or TargetProcessName endswith ":\\Windows\\System32\\wininit.exe" or TargetProcessName endswith ":\\Windows\\System32\\winlogon.exe") or isnull(TargetProcessName))))

Required Data Sources

False Positive Guidance

• Unknown

MITRE ATT&CK Context

• Tactic: Initial Access
• Tactic: Lateral Movement
• Technique: T1190 — T1190
• Technique: T1210 — T1210

References

• https://securingtomorrow.mcafee.com/other-blogs/mcafee-labs/rdp-stands-for-really-do-patch-understanding-the-wormable-rdp-vulnerability-cve-2019-0708/
• SigmaHQ Rule