cscli scenarios install sigmahq/proc_creation_win_powershell_base64_mppreference1type: trigger2name: sigmahq/proc_creation_win_powershell_base64_mppreference3description: |4 Detects base64 encoded "MpPreference" PowerShell cmdlet code that tries to modifies or tamper with Windows Defender AV5filter: |6 (evt.Meta.service == 'sysmon' && evt.Parsed.EventID == '1') && (evt.Parsed.CommandLine contains 'QWRkLU1wUHJlZmVyZW5jZS' || evt.Parsed.CommandLine contains 'FkZC1NcFByZWZlcmVuY2Ug' || evt.Parsed.CommandLine contains 'BZGQtTXBQcmVmZXJlbmNlI' || evt.Parsed.CommandLine contains 'U2V0LU1wUHJlZmVyZW5jZS' || evt.Parsed.CommandLine contains 'NldC1NcFByZWZlcmVuY2Ug' || evt.Parsed.CommandLine contains 'TZXQtTXBQcmVmZXJlbmNlI' || evt.Parsed.CommandLine contains 'YWRkLW1wcHJlZmVyZW5jZS' || evt.Parsed.CommandLine contains 'FkZC1tcHByZWZlcmVuY2Ug' || evt.Parsed.CommandLine contains 'hZGQtbXBwcmVmZXJlbmNlI' || evt.Parsed.CommandLine contains 'c2V0LW1wcHJlZmVyZW5jZS' || evt.Parsed.CommandLine contains 'NldC1tcHByZWZlcmVuY2Ug' || evt.Parsed.CommandLine contains 'zZXQtbXBwcmVmZXJlbmNlI' || evt.Parsed.CommandLine contains 'QQBkAGQALQBNAHAAUAByAGUAZgBlAHIAZQBuAGMAZQAgA' || evt.Parsed.CommandLine contains 'EAZABkAC0ATQBwAFAAcgBlAGYAZQByAGUAbgBjAGUAIA' || evt.Parsed.CommandLine contains 'BAGQAZAAtAE0AcABQAHIAZQBmAGUAcgBlAG4AYwBlACAA' || evt.Parsed.CommandLine contains 'UwBlAHQALQBNAHAAUAByAGUAZgBlAHIAZQBuAGMAZQAgA' || evt.Parsed.CommandLine contains 'MAZQB0AC0ATQBwAFAAcgBlAGYAZQByAGUAbgBjAGUAIA' || evt.Parsed.CommandLine contains 'TAGUAdAAtAE0AcABQAHIAZQBmAGUAcgBlAG4AYwBlACAA' || evt.Parsed.CommandLine contains 'YQBkAGQALQBtAHAAcAByAGUAZgBlAHIAZQBuAGMAZQAgA' || evt.Parsed.CommandLine contains 'EAZABkAC0AbQBwAHAAcgBlAGYAZQByAGUAbgBjAGUAIA' || evt.Parsed.CommandLine contains 'hAGQAZAAtAG0AcABwAHIAZQBmAGUAcgBlAG4AYwBlACAA' || evt.Parsed.CommandLine contains 'cwBlAHQALQBtAHAAcAByAGUAZgBlAHIAZQBuAGMAZQAgA' || evt.Parsed.CommandLine contains 'MAZQB0AC0AbQBwAHAAcgBlAGYAZQByAGUAbgBjAGUAIA' || evt.Parsed.CommandLine contains 'zAGUAdAAtAG0AcABwAHIAZQBmAGUAcgBlAG4AYwBlACAA')7blackhole: 2m8#status: test9labels:10 service: windows11 confidence: 112 spoofable: 013 classification:14 - attack.t1562.0011516 label: "Powershell Base64 Encoded MpPreference Cmdlet"17 behavior : "windows:audit"18 remediation: false1920scope:21 type: ParentProcessId22 expression: evt.Parsed.ParentProcessId2324