Sublime Security high experimental mql

Attachment: HTML file with reference to recipient and suspicious patterns

Attached HTML file (or HTML file within an attached email) contains references to the recipients email address, indicative of credential phishing, and suspicious Javascript patterns.

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Detection Logic

type.inbound
and any(attachments,
        (
          .content_type == "text/html"
          or (.content_type == "message/rfc822" or .file_extension in ('eml'))
          or .file_extension in~ ("html", "htm", "shtml", "dhtml")
          or .file_type == "html"
        )
        and any(file.explode(.),
                .flavors.mime in~ ("text/html", "text/plain")
                and any(recipients.to,
                        any(..scan.strings.strings,
                            strings.icontains(., ..email.email)
                        )
                        and (
                          .email.domain.valid
                          or strings.icontains(.display_name, "undisclosed")
                        )
                )
        )
        and any(file.explode(.),
                (
                  any(.flavors.yara, . == "javascript_file")
                  // common indicator of HTML smuggling
                  and length(filter(.scan.javascript.identifiers,
                                    strings.ilike(., "_0x*")
                             )
                  ) > 50
                )
                or (
                  // javascript that doesn't get pulled out properly
                  .flavors.mime == "text/plain"
                  and strings.ilike(.file_name, "script*")
                  // common indicator of HTML smuggling
                  and length(filter(.scan.strings.strings,
                                    regex.imatch(., ".*_0x.*")
                             )
                  ) > 50
                )
        )
)

Field Validations

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