• Sublime Core Feed
High Severity

VIP impersonation with urgent request (untrusted sender)

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Description

Sender is using a display name that matches the display name of someone in your $org_vips list.

Detects potential Business Email Compromise (BEC) attacks by analyzing text within email body from untrusted senders.

References

No references.

Sublime Security
Created Aug 17th, 2023 • Last updated Apr 8th, 2024
Feed Source
Sublime Core Feed
Source
GitHub
type.inbound
and any($org_vips, .display_name =~ sender.display_name)
and (
  any(ml.nlu_classifier(body.current_thread.text).intents,
      .name == "bec" and .confidence in ("medium", "high")
  )
  or (
    any(ml.nlu_classifier(body.current_thread.text).entities,
        .name == "urgency"
    )
    and any(ml.nlu_classifier(body.current_thread.text).entities,
            .name == "request"
    )
  )
)
and (
  (
    profile.by_sender().prevalence != "common"
    and not profile.by_sender().solicited
  )
  or (
    profile.by_sender().any_messages_malicious_or_spam
    and not profile.by_sender().any_false_positives
  )
)

// negate highly trusted sender domains unless they fail DMARC authentication
and (
  (
    sender.email.domain.root_domain in $high_trust_sender_root_domains
    and (
      any(distinct(headers.hops, .authentication_results.dmarc is not null),
          strings.ilike(.authentication_results.dmarc, "*fail")
      )
    )
  )
  or sender.email.domain.root_domain not in $high_trust_sender_root_domains
)

and not profile.by_sender().any_false_positives

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