Cisco Talos reports a rise in email threats using hidden text salting to evade detection. This technique involves inserting invisible characters or comments in the HTML of emails, confusing parsers and spam filters. It tricks systems into misidentifying brand names and languages in phishing attempts. Success against this method requires advanced detection strategies, inspecting suspicious CSS properties, and utilizing AI-driven email security solutions.
https://blog.talosintelligence.com/seasoning-email-threats-with-hidden-text-salting/