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Detection rules › Sigma

Suspicious MSDT Parent Process

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

Detects msdt.exe executed by a suspicious parent as seen in CVE-2022-30190 / Follina exploitation

MITRE ATT&CK coverage

TacticTechniques
StealthT1036 Masquerading, T1218 System Binary Proxy Execution

Event coverage

ProviderEventTitle
SysmonEvent ID 1Process creation

Rule body yaml

title: Suspicious MSDT Parent Process
id: 7a74da6b-ea76-47db-92cc-874ad90df734
status: test
description: Detects msdt.exe executed by a suspicious parent as seen in CVE-2022-30190 / Follina exploitation
references:
    - https://twitter.com/nao_sec/status/1530196847679401984
    - https://app.any.run/tasks/713f05d2-fe78-4b9d-a744-f7c133e3fafb/
author: Nextron Systems
date: 2022-06-01
modified: 2023-02-06
tags:
    - attack.stealth
    - attack.t1036
    - attack.t1218
logsource:
    category: process_creation
    product: windows
detection:
    selection_parent:
        ParentImage|endswith:
            - '\cmd.exe'
            - '\cscript.exe'
            - '\mshta.exe'
            - '\powershell.exe'
            - '\pwsh.exe'
            - '\regsvr32.exe'
            - '\rundll32.exe'
            - '\schtasks.exe'
            - '\wmic.exe'
            - '\wscript.exe'
            - '\wsl.exe'
            # Note: office applications are covered by: 438025f9-5856-4663-83f7-52f878a70a50
    selection_msdt:
        - Image|endswith: '\msdt.exe'
        - OriginalFileName: 'msdt.exe'
    condition: all of selection_*
falsepositives:
    - Unknown
level: high

Stages and Predicates

Stage 0: condition

all of selection_*

Stage 1: selection_parent

selection_parent:
    ParentImage|endswith:
        - '\cmd.exe'
        - '\cscript.exe'
        - '\mshta.exe'
        - '\powershell.exe'
        - '\pwsh.exe'
        - '\regsvr32.exe'
        - '\rundll32.exe'
        - '\schtasks.exe'
        - '\wmic.exe'
        - '\wscript.exe'
        - '\wsl.exe'

Stage 2: selection_msdt

selection_msdt:
    - Image|endswith: '\msdt.exe'
    - OriginalFileName: 'msdt.exe'

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
Imageends_with
  • \msdt.exe corpus 9 (sigma 9)
OriginalFileNameeq
  • msdt.exe corpus 8 (sigma 6, elastic 2)
ParentImageends_with
  • \cmd.exe corpus 20 (sigma 20)
  • \cscript.exe corpus 17 (sigma 17)
  • \mshta.exe corpus 13 (sigma 13)
  • \powershell.exe corpus 24 (sigma 24)
  • \pwsh.exe corpus 21 (sigma 21)
  • \regsvr32.exe corpus 11 (sigma 11)
  • \rundll32.exe corpus 15 (sigma 15)
  • \schtasks.exe
  • \wmic.exe
  • \wscript.exe corpus 19 (sigma 19)
  • \wsl.exe corpus 4 (sigma 4)