sigmamediumHunting

Suspicious IO.FileStream

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.

MITRE ATT&CK

T1070.003

defense-evasion

Detection Query

selection:
  ScriptBlockText|contains|all:
    - New-Object
    - IO.FileStream
    - \\\\.\\
condition: selection

Author

frack113

Created

2022-01-09

Data Sources

windowsps_script

Platforms

windows

References

https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1006/T1006.md

Tags

attack.defense-evasionattack.t1070.003

Raw Content

title: Suspicious IO.FileStream
id: 70ad982f-67c8-40e0-a955-b920c2fa05cb
status: test
description: 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://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1006/T1006.md
author: frack113
date: 2022-01-09
modified: 2022-03-05
tags:
    - attack.defense-evasion
    - 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:
    - Legitimate PowerShell scripts
level: medium