Brand impersonation: Vanguard

name: "Brand impersonation: Vanguard"
description: "Detects inbound messages from senders using Vanguard-like display names or domains, excluding legitimate Vanguard domains and authenticated communications. Additional checks ensure the sender is not from trusted organizational domains or high-trust sender domains with proper authentication."
type: "rule"
severity: "medium"
source: |
  type.inbound
  and (
    // display name contains Vanguard
    (
      strings.ilike(strings.replace_confusables(sender.display_name),
                    '*vanguard*'
      )
      // levenshtein distance similar to Vanguard
      or strings.ilevenshtein(strings.replace_confusables(sender.display_name),
                              'vanguard'
      ) <= 1
      // sender domain contains Vanguard
      or strings.ilike(strings.replace_confusables(sender.email.domain.domain),
                       '*vanguard*'
      )
    )
  )
  and (
    (
      any(beta.ml_topic(body.current_thread.text).topics,
          .name in (
            "Security and Authentication",
            "Secure Message",
            "Financial Communications"
          )
          and .confidence == "high"
      )
      or any(beta.ml_topic(beta.ocr(file.message_screenshot()).text).topics,
             .name in (
               "Security and Authentication",
               "Secure Message",
               "Financial Communications"
             )
             and .confidence == "high"
      )
    )
    and (
      any(ml.nlu_classifier(body.current_thread.text).intents,
          .name == "cred_theft" and .confidence == "high"
      )
      or any(ml.nlu_classifier(beta.ocr(file.message_screenshot()).text).intents,
             .name == "cred_theft" and .confidence == "high"
      )
    )
  )
  
  // and the sender is not in org_domains or from Vanguard domains and passes auth
  and not (
    sender.email.domain.root_domain in $org_domains
    or (
      sender.email.domain.root_domain in (
        "vanguard.com",
        "vanguardcharitable.org", // philanthropic giving arm
        "vanguardmexico.com",
        "vanguardcanada.ca",
        "vanguard.co.uk",
        "vanguard.com.au",
        "vanguard.com.hk",
        "vanguardinvestor.co.uk",
        "vanguardretirement-mail.com",
        "e-vanguard.com",
        "e-vanguardcharitable.org",
        "feedback-vanguard.com",
        "m-vanguard.com",
        "investordelivery.com",
        "retsupport.com",
        "vanguardretirement.com"
      )
      and headers.auth_summary.dmarc.pass
    )
    or (
      sender.display_name == "Vanguard Visa Law"
      and sender.email.domain.root_domain == "docketwise.com"
    )
  )
  // 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
  )
  and not profile.by_sender().solicited

attack_types:
  - "BEC/Fraud"
  - "Callback Phishing"
  - "Credential Phishing"
  - "Extortion"
  - "Malware/Ransomware"
  - "Spam"
tactics_and_techniques:
  - "Impersonation: Brand"
detection_methods:
  - "Natural Language Understanding"
  - "Header analysis"
  - "Sender analysis"
id: "3bd048fe-5b3e-5050-b0d6-669653e14d9a"