• Sublime Core Feed
Medium Severity

Credential theft with 'safe content' deception and social engineering topics

Description

Detects messages containing credential theft language combined with social engineering topics like secure messages, notifications, or authentication alerts. The rule specifically identifies emails that deceptively claim to be from a 'safe sender' or contain 'safe content' in the first line, which is a common tactic used to bypass security filters and gain user trust.

References

No references.

Sublime Security
Created Jan 5th, 2026 • Last updated Jan 5th, 2026
Source
type.inbound
and any(ml.nlu_classifier(body.current_thread.text).intents,
        .name == "cred_theft" and .confidence != "low"
)
and (
  any(ml.nlu_classifier(body.current_thread.text).topics,
      .name in (
        "Reminders and Notifications",
        "Secure Message",
        "Security and Authentication",
        "Voicemail Call and Missed Call Notifications",
        "E-Signature",
        "Financial Communications"
      )
  )
  or (
    length(distinct(filter(ml.nlu_classifier(body.current_thread.text).entities,
                           .name not in ("org", "recipient", "sender")
                    ),
                    .name
           )
    ) > 0
    and all(distinct(filter(ml.nlu_classifier(body.current_thread.text).entities,
                            .name not in ("org", "recipient", "sender")
                     ),
                     .name
            ),
            .name in ("request", "financial", "urgency")
    )
  )
)
and not any(ml.nlu_classifier(body.current_thread.text).topics,
            .name in (
              "Advertising and Promotions",
              "Newsletters and Digests",
              "News and Current Events",
              "Travel and Transportation"
            )
)
// check only the first line of the email
and any(regex.iextract(body.current_thread.text, "^[^\r\n]*"),
        length(.full_match) < 500
        and strings.ilike(.full_match,
                          "*safe content*",
                          "*safe sender*",
                          "*trusted sender*"
        )
        and not regex.icontains(.full_match,
                                "add.{0,50} to.{0,50}(address book|safe senders? list)"
        )
)
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