Analysis · curated 16 Sep 2026
What is ASCII smuggling, and how is it helping spammers bypass AI email filters? | Technology News - The Indian Express
First reported indianexpress.com
Coverage timeline
Single-source analysis — first reported, latest, and curated coincide.
Why it matters
ASCII smuggling shows how an AI-era prompt-injection obfuscation technique is being repurposed to bypass AI-powered email filters at scale, keeping spam and phishing an ongoing challenge for defenders.
The Indian Express explains ASCII smuggling, an evasion technique in which invisible Unicode tag characters are inserted to prevent email filters from parsing content, which Microsoft reported was used in a high-volume phishing campaign. Microsoft noted the same mechanism has been used to hide malicious prompts in prompt-injection attacks on AI agents, and that ASCII smuggling signatures detected by Microsoft Defender for Office spiked from ~21,000 to over 2.5 million per day in early 2026.