Criminals are using CSS to get around filters and track email usage

Cisco Talos says hackers are abusing CSS in emails The stylesheet language is used to hide content, track people's behavior, ...
Security Boulevard

NDSS 2025 – Exploiting the Complexity Of Modern CSS For Email And Browser Fingerprinting

Leon Trampert (CISPA Helmholtz Center for Information Security), Daniel Weber (CISPA Helmholtz Center for Information Security), Lukas Gerlach (CISPA Helmholtz Center for Information Security), ...
Dark Reading

Attackers Use Unicode & HTML to Bypass Email Security Tools

Cybercriminals have been spotted using HTML/CSS and Unicode tricks to bypass tools meant to block malicious emails, marking a new twist in phishing techniques, security researchers report. Attackers ...