Unicode Tags Characters

A Technique for Hiding Instructions from AI Models Is Used to Bypass Phishing Filters

Microsoft researchers identified a widespread financial phishing campaign that used invisible Unicode characters from the Tags block to split words such as funding before messages were analyzed, repurposing a technique known from prompt-injection attacks against artificial intelligence models. Related detections rose from approximately 21,000 messages to more than 1.3 million messages on February 9, 2026.