Suspicious IO.FileStream (via ps_script)

title: Suspicious IO.FileStream (via ps_script)
id: a7089e88-78a3-590d-804e-517823d386ed
status: stable
description: This rule detects open a handle on the drive volume via the \\.\ DOS device path specifier and perform direct access read of the first few bytes of the volume.
references:
    - https://attack.mitre.org/techniques/T1070/003/
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1006/T1006.md
author: Huntrule Team
date: 2026-06-17
tags:
    - attack.stealth
    - attack.t1070.003
logsource:
    product: windows
    category: ps_script
    definition: 'Requirements: Script Block Logging must be enabled'
detection:
    selection:
        ScriptBlockText|contains|all:
            - New-Object
            - IO.FileStream
            - '\\\\.\\'
    condition: selection
falsepositives:
    - Unknown
level: medium