Medium Severity

Link: PDF file disguised as HTML page

Labels

Credential Phishing
Malware/Ransomware
Evasion
PDF
URL analysis
Content analysis

Description

Detects inbound messages containing links that appear to reference PDF files but are actually HTML pages, indicated by URLs ending with '.pdf' followed by additional characters and '.html'. This technique is commonly used to bypass security filters and deceive recipients into believing they are accessing a legitimate PDF document.

References

No references.

Sublime Security
Created Jun 5th, 2026 • Last updated Jun 5th, 2026
Feed Source
Sublime Core Feed
Source
GitHub
type.inbound
and any(body.current_thread.links,
        regex.icontains(.href_url.path, '\.pdf[^/]*\.html$')
)
MQL Rule Console
•Docs•Learning 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.

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