Brand impersonation: Charles Schwab

name: "Brand impersonation: Charles Schwab"
description: "Impersonation of Charles Schwab & Co"
type: "rule"
severity: "medium"
source: |
  type.inbound
  and (
    // display name contains charles schwab
    (
      strings.ilike(strings.replace_confusables(sender.display_name),
                    '*charles schwab*'
      )
      // no spaces
      or strings.ilike(strings.replace_confusables(sender.display_name),
                       '*charlesschwab*'
      )
      // levenshtein distince similar to schwab
      or strings.ilevenshtein(strings.replace_confusables(sender.display_name),
                              'charles schwab'
      ) <= 1
      // sender domain contains schwab
      or strings.ilike(strings.replace_confusables(sender.email.domain.domain),
                       '*schwab*'
      )
    )
  )
  
  // and the sender is not in org_domains or from charles shwab domains and passes auth
  and not (
    sender.email.domain.root_domain in $org_domains
    or (
      (
        sender.email.domain.root_domain in (
          "schwab.com",
          "aboutschwab.com.",
          "schwabcorrentesettlement.com", // Schawb v. Corrente, et al. Settlement domain
          "schwabmoneywise.com",
          "schwabe.com", // law firm with name
          "proxyvote.com", // sends shareholder voting information with subject of company name
          "boheme-schwabing.de", // steakhouse
          "lesschwab.com", // tire sales
          "schwab-marketing.com", // German Marketing Agency
          "schwaben.ca" // unrelated but similar domain
        )
        or sender.email.domain.domain in ("schwabebooks.ccsend.com")
      )
      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
  )
  and not profile.by_sender().solicited

attack_types:
  - "Credential Phishing"
tactics_and_techniques:
  - "Impersonation: Brand"
  - "Lookalike domain"
  - "Social engineering"
detection_methods:
  - "Header analysis"
  - "Sender analysis"
id: "7abde595-bd69-5b79-8031-2c5a12b1767e"