decode data using Base64 in .NET

rule:
  meta:
    name: decode data using Base64 in .NET
    namespace: data-manipulation/encoding/base64
    authors:
      - michael.hunhoff@mandiant.com
    scopes:
      static: function
      dynamic: call
    att&ck:
      - Defense Evasion::Deobfuscate/Decode Files or Information [T1140]
    mbc:
      - Data::Decode Data::Base64 [C0053.001]
  features:
    - or:
      - api: System.Convert::FromBase64String
      - api: System.Convert::FromBase64CharArray
      - api: System.Convert::TryFromBase64Chars
      - api: System.Convert::TryFromBase64String