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AWL Bypass with Winrm.vbs and Malicious WsmPty.xsl/WsmTxt.xsl

Detects execution of attacker-controlled WsmPty.xsl or WsmTxt.xsl via winrm.vbs and copied cscript.exe (can be renamed)

MITRE ATT&CK

T1216
defense-evasion

Detection Query

contains_format_pretty_arg:
  CommandLine|contains:
    - format:pretty
    - format:"pretty"
    - format:"text"
    - format:text
image_from_system_folder:
  Image|startswith:
    - C:\Windows\System32\
    - C:\Windows\SysWOW64\
contains_winrm:
  CommandLine|contains: winrm
condition: contains_winrm and (contains_format_pretty_arg and not
  image_from_system_folder)

Author

Julia Fomina, oscd.community

Created

2020-10-06

Data Sources

windowsProcess Creation Events

Platforms

windows

References

Tags

attack.defense-evasionattack.t1216
Raw Content
title: AWL Bypass with Winrm.vbs and Malicious WsmPty.xsl/WsmTxt.xsl
id: 074e0ded-6ced-4ebd-8b4d-53f55908119d
status: test
description: Detects execution of attacker-controlled WsmPty.xsl or WsmTxt.xsl via winrm.vbs and copied cscript.exe (can be renamed)
references:
    - https://posts.specterops.io/application-whitelisting-bypass-and-arbitrary-unsigned-code-execution-technique-in-winrm-vbs-c8c24fb40404
author: Julia Fomina, oscd.community
date: 2020-10-06
modified: 2022-10-09
tags:
    - attack.defense-evasion
    - attack.t1216
logsource:
    category: process_creation
    product: windows
detection:
    contains_format_pretty_arg:
        CommandLine|contains:
            - 'format:pretty'
            - 'format:"pretty"'
            - 'format:"text"'
            - 'format:text'
    image_from_system_folder:
        Image|startswith:
            - 'C:\Windows\System32\'
            - 'C:\Windows\SysWOW64\'
    contains_winrm:
        CommandLine|contains: 'winrm'
    condition: contains_winrm and (contains_format_pretty_arg and not image_from_system_folder)
falsepositives:
    - Unlikely
level: medium