diff --git a/detection-rules/body_business_email_compromise_unsolicited.yml b/detection-rules/body_business_email_compromise_unsolicited.yml index f47916f189f..911d91397be 100644 --- a/detection-rules/body_business_email_compromise_unsolicited.yml +++ b/detection-rules/body_business_email_compromise_unsolicited.yml @@ -27,7 +27,20 @@ source: | ) ), ) - + + // negate "via" senders via dmarc authentication or gmail autoforwards + and ( + ( + not any(distinct(headers.hops, .authentication_results.dmarc is not null), + strings.ilike(.authentication_results.dmarc, "pass") + or not any([headers.return_path.email], + strings.ilike(headers.return_path.local_part, "*+caf_=*") + ) + ) + and strings.contains(sender.display_name, "via") + ) + ) + // unsolicited and ( ( @@ -39,6 +52,7 @@ source: | and sender.email.domain.domain not in $recipient_domains ) ) + attack_types: - "BEC/Fraud" tactics_and_techniques: