Deceptive Dropbox mention

type.inbound
and strings.icontains(body.current_thread.text, 'dropbox')
and any(beta.ml_topic(coalesce(body.html.display_text, body.current_thread.text)).topics, .name == "File Sharing and Cloud Services" and .confidence != "low")

and (
  // Email address discrepancy detection - looking for matches in the domain name from the sender but not the current thread proposed sender name
  any(regex.iextract(body.current_thread.text,
                   '(?P<whole_email>(?P<local_part>[a-zA-Z0-9._%-]+)@(?P<domain_name>[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}))'
                  ),
    strings.parse_email(.named_groups["whole_email"]).domain.domain == sender.email.domain.domain
    and strings.parse_email(.named_groups["whole_email"]).local_part != sender.email.local_part
    and not strings.parse_email(.named_groups["whole_email"]).email in~ map(filter(recipients.to, .email.domain.valid), .email.email)
  )
  // self sender
  or (
    length(recipients.to) == 1
    and sender.email.email == recipients.to[0].email.email
  )
)

// Not from legitimate Dropbox infrastructure
and sender.email.domain.root_domain not in~ (
  'dropbox.com',
  'docsend.com',
  'box.com',
  'wetransfer.com',
  // tuning: exlude hellosign emails that are covered in another rule
  'hellosign.com'
)

// Contains suspicious links to non-Dropbox/file-sharing domains
and any(body.links,
        (.href_url.domain.root_domain in~ $free_subdomain_hosts
        or .href_url.domain.root_domain in~ $free_file_hosts)
        and .href_url.domain.valid
)

// ML indicates potential credential theft
and any(ml.nlu_classifier(body.current_thread.text).intents,
        .name == "cred_theft" and .confidence != "low"
)