Create brand_impersonation_bbb.yml

detection-rules/brand_impersonation_bbb.yml

@@ -0,0 +1,44 @@
+name: "Brand impersonation: the Better Business Bureau (BBB)"
+description: "Detect impersonation of the Better Business Bureau (BBB) from unsolicited sender"
+type: "rule"
+severity: "medium"
+source: |
+  type.inbound
+  and 
+  // display name contains bbb
+  (
+    regex.icontains(strings.replace_confusables(sender.display_name),
+                    '(?:\bBBB\b|better business bureau)'
+    )
+    // or levenshtein distance similar to the full name
+    or strings.ilevenshtein(strings.replace_confusables(sender.display_name),
+                            'better business bureau'
+    ) <= 1
+  )
+  // and the sender is not in org_domains or from the bbb and passes auth
+  and not (
+    sender.email.domain.root_domain in ("bbb.org", "mybbb.org")
+    and headers.auth_summary.dmarc.pass
+  )
+
+  // and the sender is not from high trust sender root domains
+  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
+  )
+
+  // not solicited
+  and not profile.by_sender().solicited
+
+attack_types:
+  - "Credential Phishing"
+  - "BEC/Fraud"
+tactics_and_techniques:
+  - "Impersonation: Brand"
+  - "Social engineering"
+detection_methods:
+  - "Sender analysis"
+id: "76f54e5f-c937-5693-b8e7-3ced7dac61f9"