reference Base64 string

rule:
  meta:
    name: reference Base64 string
    namespace: data-manipulation/encoding/base64
    authors:
      - moritz.raabe@mandiant.com
    scopes:
      static: file
      dynamic: file
    att&ck:
      - Defense Evasion::Obfuscated Files or Information [T1027]
    mbc:
      - Data::Encode Data::Base64 [C0026.001]
      - Data::Check String [C0019]
    examples:
      - BFB9B5391A13D0AFD787E87AB90F14F5
      - 074072B261FC27B65C72671F13510C05
      - 5DB2D2BE20D59AA0BE6709A6850F1775
  features:
    - string: /ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/