Sublime Security medium experimental mql

Attachment: DocuSign impersonation via PDF linking to new domain

This rule detects PDF files containing a DocuSign logo linking to a newly created domain (Less than or equal to 3 days)

View Source

Detection Logic

type.inbound
and any(attachments,
        .file_type == "pdf"
        and any(ml.logo_detect(.).brands, .name == "DocuSign")
        and any(file.explode(.),
                any(.scan.pdf.urls, network.whois(.domain).days_old <= 3)
        )
)

// 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
)

// excludes senders that contain "via" in the display name a resilient way
and not (
  any(headers.hops,
      any(.fields,
          .name == "X-Api-Host" and strings.ends_with(.value, "docusign.net")
      )
  )
)

Field Validations

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