reference Quad9 DNS server

rule:
  meta:
    name: reference Quad9 DNS server
    namespace: communication/dns
    authors:
      - william.ballenthin@mandiant.com
    scopes:
      static: function
      dynamic: span of calls
    references:
      - https://www.techradar.com/news/best-dns-server
  features:
    - or:
      - string: "9.9.9.9"
      - string: "149.112.112.112"