Suspicious Unblock-File

Title: Suspicious Unblock-File
Status: test
Description:Remove the Zone.Identifier alternate data stream which identifies the file as downloaded from the internet.
References:
  -https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1553.005/T1553.005.md#atomic-test-3---remove-the-zoneidentifier-alternate-data-stream
  -https://learn.microsoft.com/en-us/powershell/module/microsoft.powershell.utility/unblock-file?view=powershell-7.2
Author: frack113
Date: 2022-02-01
modified:None
Tags:

• -'attack.defense-impairment'
• -'attack.t1553.005'

Logsource:

• product: windows
• category: ps_script
• definition: Requirements: Script Block Logging must be enabled

Detection:
  selection:
    ScriptBlockText|contains|all:
      -'Unblock-File '
      -'-Path '

  condition:selection
Falsepositives:
  -Legitimate PowerShell scripts
Level: medium