Reconnaissance: All recipients cc/bcc'd or undisclosed

type.inbound
and (
  length(recipients.bcc) > 0
  or length(recipients.cc) > 0
  or any(recipients.to, strings.ilike(.display_name, "undisclosed?recipients"))
)
and (
  length(subject.base) <= 10
  or (
    (
      strings.ilike(subject.base, "*checking*", "*testing*")
      or subject.base == body.current_thread.text
    )
    and length(subject.base) <= 25
  )
)
and length(attachments) == 0
// and there are no links. Or all the links are to aka.ms or an extraction from a warning banner that match the senders domain
and (
  length(body.links) == 0
  or length(filter(body.links,
                   (
                     .display_text is null
                     and .display_url.url == sender.email.domain.root_domain
                   )
                   or .href_url.domain.domain == "aka.ms"
            )
  ) == length(body.links)
)
and (
  body.current_thread.text is null
  or length(body.current_thread.text) < 50
  or (
    length(body.current_thread.text) < 900
    // or body is most likely all warning banner ending with a generic greeting
    and regex.imatch(body.current_thread.text, '.*(hi|hello)')
  )
  // body length without disclaimer is shorter than 50 characters
  or (
    any(map(filter(ml.nlu_classifier(body.current_thread.text).entities,
                   .name == "disclaimer"
            ),
            .text
        ),
        (length(body.current_thread.text) - length(.)) < 50
    )
  )
  // matching nlu_classifier 'bec' to smaller messages less than 200
  or (
    any(ml.nlu_classifier(body.current_thread.text).intents,
        .name == "bec" and .confidence in ("high", "medium")
    )
    and length(body.current_thread.text) < 200
    and not regex.icontains(body.html.raw,
                            '(?:<div data-smartmail=|gmail_signature(?:_[^"]*)?)'
    ) // not condition to exclude smaller messages with a legitimate email signature
    and length(body.previous_threads) == 0 // excluding messages with simple responses to other threads
  )
)
and profile.by_sender().prevalence != "common"
and not profile.by_sender().solicited
and not profile.by_sender().any_messages_benign

// negate highly trusted sender domains unless they fail DMARC authentication
and (
  (
    sender.email.domain.root_domain in $high_trust_sender_root_domains
    and not headers.auth_summary.dmarc.pass
  )
  or sender.email.domain.root_domain not in $high_trust_sender_root_domains
)