Convert indexed Sigma rules into analyst-ready detections.

title: Diskshadow Script Mode - Uncommon Script Extension Execution
id: 1dde5376-a648-492e-9e54-4241dd9b0c7f
related:
    - id: fa1a7e52-3d02-435b-81b8-00da14dd66c1 # Diskshadow Script Mode - Execution From Potential Suspicious Location
      type: similar
    - id: 9f546b25-5f12-4c8d-8532-5893dcb1e4b8 # Potentially Suspicious Child Process Of DiskShadow.EXE
      type: similar
    - id: 56b1dde8-b274-435f-a73a-fb75eb81262a # Diskshadow Child Process Spawned
      type: similar
    - id: 0c2f8629-7129-4a8a-9897-7e0768f13ff2 # Diskshadow Script Mode Execution
      type: similar
status: test
description: |
    Detects execution of "Diskshadow.exe" in script mode to execute an script with a potentially uncommon extension.
    Initial baselining of the allowed extension list is required.
references:
    - https://bohops.com/2018/03/26/diskshadow-the-return-of-vss-evasion-persistence-and-active-directory-database-extraction/
    - https://www.ired.team/offensive-security/credential-access-and-credential-dumping/ntds.dit-enumeration
    - https://medium.com/@cyberjyot/lolbin-execution-via-diskshadow-f6ff681a27a4
    - https://learn.microsoft.com/en-us/windows-server/administration/windows-commands/diskshadow
    - https://www.lifars.com/wp-content/uploads/2022/01/GriefRansomware_Whitepaper-2.pdf
    - https://www.zscaler.com/blogs/security-research/technical-analysis-crytox-ransomware
    - https://research.checkpoint.com/2022/evilplayout-attack-against-irans-state-broadcaster/
author: Nasreddine Bencherchali (Nextron Systems)
date: 2023-09-15
modified: 2024-03-05
tags:
    - attack.defense-evasion
    - attack.t1218
logsource:
    category: process_creation
    product: windows
detection:
    selection_img:
        - OriginalFileName: 'diskshadow.exe'
        - Image|endswith: '\diskshadow.exe'
    selection_flag:
        CommandLine|contains|windash: '-s '
    filter_main_ext:
        # Note: can be changed to an "endswith" to avoid rare FPs. But you need to account for quoted paths
        # Note: Using the ".txt" is based on the MS documentation example. Best add the extension you use internally before using this rule
        CommandLine|contains: '.txt'
    condition: all of selection_* and not 1 of filter_main_*
falsepositives:
    - False postitve might occur with legitimate or uncommon extensions used internally. Initial baseline is required.
level: medium