• Sublime Core Feed

Description

Message is from a commonly abused sender TLD, contains various suspicious indicators resembling credential theft, and is unsolicited.

References

No references.

Sublime Security
Created Aug 17th, 2023 • Last updated Aug 7th, 2025
Source
type.inbound

// we don't do a suspicious link check here
// because we are seeing abuse of mass marketing tools
// like campaign[.]adobe[.]com
// once we roll out better support for unfurling those,
// we can update this logic
and length(body.links) > 0

// commonly abused sender TLD
and strings.ilike(sender.email.domain.tld, "*.jp")
and 3 of (
  // language attempting to engage
  any(ml.nlu_classifier(body.current_thread.text).entities, .name == "request"),

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

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

  // known suspicious pattern in the URL path
  any(body.links, regex.match(.href_url.path, '\/[a-z]{3}\d[a-z]')),

  // suspicious image that's most likely cred_theft
  any(attachments,
      .file_type in $file_types_images
      and any(file.explode(.),
              any(ml.nlu_classifier(.scan.ocr.raw).intents,
                  .name == "cred_theft"
              )
              or any(ml.nlu_classifier(.scan.ocr.raw).entities,
                     .name == "financial"
              )
      )
  ),

  // recipient's SLD is in the sender's display name
  any(recipients.to,
      strings.icontains(sender.display_name, .email.domain.sld)
      and (
        .email.domain.valid or strings.icontains(.display_name, "undisclosed")
      )
  ),

  // recipient's email address in the subject
  any(recipients.to,
      strings.icontains(subject.subject, .email.email)
      and (
        .email.domain.valid or strings.icontains(.display_name, "undisclosed")
      )
  ),
)
and (
  not profile.by_sender().solicited
  or (
    profile.by_sender().any_messages_malicious_or_spam
    and not profile.by_sender().any_messages_benign
  )
)
and not sender.email.domain.root_domain in ("amazon.co.jp")
// negate highly trusted sender domains unless they fail DMARC authentication
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
)
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