Callback Phishing via Calendar Invite

type.inbound
and length(attachments) > 0
and all(attachments, .content_type in ("text/calendar", "application/ics"))
and any(attachments,
        // extract the calendar invite description and use NLU against it
        any(regex.extract(file.parse_text(.).text,
                          'DESCRIPTION:((?:(?:\r?\n[ \t][^\r\n]*)|[^\r\n])*?)(?:\r?\n[A-Z-][A-Z0-9-]*[;:])'
            ),
            any(.groups,
                any(ml.nlu_classifier(.).intents, .name == "callback_scam")
            )
        )
)
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
)