BEC/Fraud: Penpal scam

type.inbound

// the sender or the reply-to is a freemail provider
and (
  sender.email.domain.domain in $free_email_providers
  or (
    not sender.email.domain.root_domain in $free_email_providers
    and any(headers.reply_to,
            .email.domain.root_domain in $free_email_providers
    )
  )
)

// body contains pen ?pal
and regex.contains(body.current_thread.text, 'pen\s?pal')

// and NLU Request
and any(ml.nlu_classifier(body.current_thread.text).entities,
        .name == "request"
)

// not a reply
and (length(headers.references) == 0 or headers.in_reply_to is null)

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