Detection rules › Sigma

Terminal Service Process Spawn

Status
test
Severity
high
Log source
product windows, category process_creation
Author
Florian Roth (Nextron Systems)
Source
github.com/SigmaHQ/sigma

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

MITRE ATT&CK coverage

Event coverage

ProviderEventTitle
SysmonEvent ID 1Process creation

Rule body yaml

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

Stages and Predicates

Stage 0: condition

selection and not 1 of filter_*

Stage 1: selection

selection:
    ParentCommandLine|contains|all:
        - '\svchost.exe'
        - 'termsvcs'

Stage 2: not filter_*

filter_img:
    Image|endswith:
        - '\rdpclip.exe'
        - ':\Windows\System32\csrss.exe'
        - ':\Windows\System32\wininit.exe'
        - ':\Windows\System32\winlogon.exe'
filter_null:
    Image: null

Exclusions

Top-level NOT(...) conjuncts: predicates this rule actively suppresses.

FieldKindExcluded values
Imageends_with:\Windows\System32\csrss.exe
Imageends_with:\Windows\System32\wininit.exe
Imageends_with:\Windows\System32\winlogon.exe
Imageends_with\rdpclip.exe
Imageis_null(no value, null check)

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
ParentCommandLinematch
  • \svchost.exe
  • termsvcs