Reconnaissance: Large unknown recipient list

type.inbound
and (
  length(recipients.to) > 10
  and length(filter(recipients.to,
                    .email.domain.domain not in $org_domains
                    and .email.email not in $recipient_emails
                    and (
                      .email.domain.valid
                      or strings.icontains(.display_name, "undisclosed")
                    )
             )
  ) >= 10
)
and (
  length(subject.subject) <= 10 
  or subject.subject == body.current_thread.text
  or (subject.is_reply and length(body.previous_threads) == 0)
)
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"
                   or network.whois(.display_url.domain).days_old < 30
            )
  ) == length(body.links)
)
and (
  length(attachments) == 0
  or (
    length(attachments) == 1
    and any(attachments,
            .file_type in ("pdf", "png", "jpg", "tif", "heif", "doc", "docx")
            and any(file.explode(.),
                    length(.scan.ocr.raw) < 20
                    or length(.scan.strings.strings) == 1
            )
    )
  )
)
and (
  body.current_thread.text is null
  or length(body.current_thread.text) < 50
  // 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
    )
  )
)
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
)