Reported by 2 outlets

Timeline

1. original reporting

   ASCII smuggling crosses over from AI prompt injection to phishing evasion

   malware.news · 40d ago · September 3rd, 2026

   In this article What is ASCII smuggling? Writing a practical ASCII-smuggling signature What we observed: ASCII smuggling repurposed for phishing What is known and what is new Is there a detection gap? Mitigation and protection guidance References Learn More Microsoft researchers observed a high-volume phishing campaign using invisible Unicode tag characters , a technique popularized in AI prompt injection research as ASCII Smuggling . Instead of using these characters to hide instructions from people while exposing them to AI models, the attacker used them to split financial lure words such as ‘funding’ to prevent email filters from parsing them. The finding emerged from Microsoft Defender for Office 365 prompt injection protection research, showing how AI-era evasion techniques can surface in traditional phishing campaigns. In Microsoft telemetry, hits on a hunting signature designed to detect ASCII-smuggling increased sharply beginning February 9, 2026, and remained elevated on weekdays for approximately three months. Microsoft Defender for Office 365 telemetry showed that the majority of messages were flagged by layered protections rather than by reliance on a single Unicode-specific signal. What is

2. update from microsoft.com

   ASCII smuggling crosses over from AI prompt injection to phishing evasion

   microsoft.com · 40d ago · September 3rd, 2026

   “ASCII smuggling” refers to the use of invisible or non-rendering Unicode characters to hide content inside text that looks normal. The most abused range is the Unicode Tags block, U+E0000 to U+E007F. This block contains a shadow copy of the printable ASCII cha