• Sublime Core Feed

Description

Detects messages containing two PDF attachments where one has invoice-related naming patterns and another contains W-9 tax form indicators, with at least one PDF generated by Chrome or wkhtmltopdf tools, commonly used in business email compromise attacks targeting financial processes.

References

No references.

Sublime Security
Created Jan 21st, 2026 • Last updated Jan 21st, 2026
Source
type.inbound
and length(distinct(attachments, .sha1)) == 2
and length(filter(attachments, .file_type == "pdf")) == 2
// either of them are chrome/wkhtmltopdf
and any(filter(attachments, .file_type == "pdf"),
        beta.parse_exif(.).creator == "Chromium"
        or strings.icontains(beta.parse_exif(.).creator, "wkhtmltopdf")
        or strings.icontains(beta.parse_exif(.).creator, "HeadlessChrome")
)
and any(attachments,
        strings.istarts_with(.file_name, 'lnv')
        or strings.istarts_with(.file_name, 'inv-')
        or strings.istarts_with(.file_name, "invoice_")
        or regex.contains(.file_name, '^Invoice\s\d{8,9}')
        or regex.contains(.file_name, '^INV[0-9]{7}')
        or regex.contains(.file_name, '^INV#[0-9]{12}')
        or strings.icontains(beta.ocr(.).text, "Executive Business Coaching")
        or strings.icontains(beta.ocr(.).text, "Executive Coaching")
        or strings.icontains(beta.ocr(.).text, "Professional Services")
        or strings.icontains(beta.ocr(.).text, "Business Systems Integration")
        or strings.icontains(beta.ocr(.).text, "Consulting & Advisory")
        or strings.icontains(beta.ocr(.).text, "Zoomlnfo")
)
and any(attachments,
        .file_name == ".pdf"
        or regex.contains(beta.ocr(.).text, 'W[=-]9')
        or regex.icontains(.file_name, 'w-?9')
)
and not (
  sender.email.domain.root_domain in ('intuit.com')
  and coalesce(headers.auth_summary.dmarc.pass, false)
)
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