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Detectionmediumtest

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.

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François HubautCreated Sun Jan 09Updated Sat Mar 0570ad982f-67c8-40e0-a955-b920c2fa05cbwindows
Log Source
WindowsPowerShell Script
ProductWindows← raw: windows
CategoryPowerShell Script← raw: ps_script

Definition

Requirements: Script Block Logging must be enabled

Detection Logic
Detection Logic1 selector
detection:
    selection:
        ScriptBlockText|contains|all:
            - New-Object
            - IO.FileStream
            - '\\\\.\\'
    condition: selection
False Positives

Legitimate PowerShell scripts

References
1
Resolving title…
github.com
MITRE ATT&CK
Rule Metadata
Rule ID
70ad982f-67c8-40e0-a955-b920c2fa05cb
Status
test
Level
medium
Type
Detection
Created
Sun Jan 09
Modified
Sat Mar 05
Author
François Hubaut
Path
rules/windows/powershell/powershell_script/posh_ps_susp_iofilestream.yml
Raw Tags
attack.defense-evasionattack.t1070.003
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