Medium Severity

Link: Hex-encoded recipient email in URL fragment

Description

Detects messages where a link in the body contains the recipient's email address hex-encoded in the URL fragment, a technique used to auto-populate or validate the target on a credential harvesting page. This pattern commonly appears in fake password expiration or account notice lures that direct victims to spoofed login pages pre-filled with their own address to increase credibility.

References

No references.

Sublime Security
Created Sep 16th, 2026 • Last updated Sep 16th, 2026
Source
type.inbound
and any(body.links,
        strings.decode_hex(.href_url.fragment) == recipients.to[0].email.email
)
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