• Sublime Core Feed
High Severity

Link: QR code in EML attachment with credential phishing indicators

Description

This rule detects QR codes in EML attachments that return a phishing disposition when analyzed, or are leveraging a known open redirect.

References

No references.

Sublime Security
Created Feb 7th, 2024 • Last updated Dec 2nd, 2025
Source
type.inbound
and length(attachments) == 1
and any(attachments,
        (.content_type == "message/rfc822" or .file_extension =~ "eml")
        // credential theft language in the attached EML
        and any(file.explode(.),
                .depth > 0
                and .scan.qr.type == "url"

                // linkanalysis phishing disposition
                and (
                  ml.link_analysis(.scan.qr.url).credphish.disposition == "phishing"
                  or (
                    strings.ilike(ml.link_analysis(.scan.qr.url).final_dom.display_text,
                                  "*robot*",
                                  "*session check*",
                                  "*verify*",
                                  "*human*"
                    )
                    and length(ml.link_analysis(.scan.qr.url).final_dom.display_text
                    ) < 250
                  )
                  or any(ml.link_analysis(.scan.qr.url).unique_urls_accessed,
                         .domain.domain == "challenges.cloudflare.com"
                         and strings.icontains(.path, "turnstile")
                  )
                  or any(.scan.qr.url.rewrite.encoders,
                         strings.icontains(., "open_redirect")
                  )
                )
                and .scan.qr.url.domain.root_domain not in $org_domains
        )
)
MQL Rule Console
DocsLearning Labs

Playground

Test against your own EMLs or sample data.

Share

Post about this on your socials.

Get Started. Today.

Managed or self-managed. No MX changes.

Deploy and integrate a free Sublime instance in minutes.
Get Started