title: Powershell Defender Exclusion
author: Florian Roth
date: 2021/04/29
description: Detects requests to exclude files, folders or processes from Antivirus
  scanning using PowerShell cmdlets
detection:
  SELECTION_1:
    EventID: 1
  SELECTION_2:
    EventID: 1
  SELECTION_3:
    CommandLine: '*Add-MpPreference *'
  SELECTION_4:
    CommandLine:
    - '* -ExclusionPath *'
    - '* -ExclusionExtension *'
    - '* -ExclusionProcess *'
  SELECTION_5:
    CommandLine:
    - '*QWRkLU1wUHJlZmVyZW5jZ*'
    - '*FkZC1NcFByZWZlcmVuY2*'
    - '*BZGQtTXBQcmVmZXJlbmNl*'
  condition: (SELECTION_1 and ((SELECTION_2 and SELECTION_3 and SELECTION_4) or SELECTION_5))
falsepositives:
- Possible Admin Activity
- Other Cmdlets that may use the same parameters
id: 17769c90-230e-488b-a463-e05c08e9d48f
level: high
logsource:
  category: process_creation
  product: windows
modified: 2021/07/12
references:
- https://docs.microsoft.com/en-us/microsoft-365/security/defender-endpoint/configure-process-opened-file-exclusions-microsoft-defender-antivirus
- https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1562.001/T1562.001.md
status: experimental
tags:
- attack.defense_evasion
- attack.t1562.001
ruletype: SIGMA