Sigma Rule Library

Suspicious MSHTA Child Process

Detects a suspicious process spawning from an "mshta.exe" process, which could be indicative of a malicious HTA script execution

View on GitHubOpen raw file

Detection logic

selection_parent

ParentImage|endswith: \mshta.exe

selection_child

- Image|endswith:
    - \cmd.exe
    - \powershell.exe
    - \pwsh.exe
    - \wscript.exe
    - \cscript.exe
    - \sh.exe
    - \bash.exe
    - \reg.exe
    - \regsvr32.exe
    - \bitsadmin.exe
- OriginalFileName:
    - Cmd.Exe
    - PowerShell.EXE
    - pwsh.dll
    - wscript.exe
    - cscript.exe
    - Bash.exe
    - reg.exe
    - REGSVR32.EXE
    - bitsadmin.exe

Condition

all of selection*

Raw YAML

title: Suspicious MSHTA Child Process
id: 03cc0c25-389f-4bf8-b48d-11878079f1ca
status: test
description: Detects a suspicious process spawning from an "mshta.exe" process, which could be indicative of a malicious HTA script execution
references:
    - https://www.trustedsec.com/july-2015/malicious-htas/
author: Michael Haag
date: 2019-01-16
modified: 2023-02-06
tags:
    - attack.stealth
    - attack.t1218.005
    - car.2013-02-003
    - car.2013-03-001
    - car.2014-04-003
logsource:
    category: process_creation
    product: windows
detection:
    selection_parent:
        ParentImage|endswith: '\mshta.exe'
    selection_child:
        - Image|endswith:
              - '\cmd.exe'
              - '\powershell.exe'
              - '\pwsh.exe'
              - '\wscript.exe'
              - '\cscript.exe'
              - '\sh.exe'
              - '\bash.exe'
              - '\reg.exe'
              - '\regsvr32.exe'
              - '\bitsadmin.exe'
        - OriginalFileName:
              - 'Cmd.Exe'
              - 'PowerShell.EXE'
              - 'pwsh.dll'
              - 'wscript.exe'
              - 'cscript.exe'
              - 'Bash.exe'
              - 'reg.exe'
              - 'REGSVR32.EXE'
              - 'bitsadmin.exe'
    condition: all of selection*
falsepositives:
    - Printer software / driver installations
    - HP software
level: high

False positives

  • Printer software / driver installations
  • HP software

References

Similar rules