BEC: Employee impersonation with subject manipulation

type.inbound

// attacks have been observed where the impersonation is
// in the subject, and the display name contains what a
// subject typically would contain. this is an attempt to
// bypass impersonation detections
and subject.subject in~ $org_display_names
and any(ml.nlu_classifier(body.current_thread.text).intents,
        .name == "bec" and .confidence in ("medium", "high")
)
and (
  not profile.by_sender().solicited
  or (
    profile.by_sender().any_messages_malicious_or_spam
    and not profile.by_sender().any_messages_benign
  )
)