Microsoft Reports Phishing Campaigns Using Invisible Unicode to Bypass Email Filters

44LENS

PreviousNext

Microsoft researchers have identified a surge in phishing campaigns using 'ASCII smuggling,' a technique that inserts invisible Unicode tag characters to evade AI-powered email filters. This method, first observed in early 2026, splits key words to prevent detection while appearing normal to users. The Unicode Tags block, originally for language tagging, is exploited to conceal malicious content. These findings highlight ongoing challenges in email security as attackers adapt AI-era evasion tactics for traditional phishing.