# ASCII smuggling crosses over from AI prompt injection to phishing evasion

DevFeed: [ASCII smuggling crosses over from AI prompt injection to phishing evasion](<https://devfeed.tech/articles/ascii-smuggling-crosses-over-from-ai-prompt-injection-to-phishing-evasion-7640.md>)

Original publisher: [Read original article](<https://www.microsoft.com/en-us/security/blog/2026/09/03/ascii-smuggling-crosses-over-from-ai-prompt-injection-to-phishing-evasion/>)

Author: Microsoft Security Research, Noam Kochavi and Sarah Wolstencroft

Published: 2026-09-03T16:00:00Z

Content type: article

Language: en

Sources: [Microsoft Security Blog](<https://devfeed.tech/sources/microsoft-security-blog.md>)

Topics: [ASCII](<https://devfeed.tech/topics/ascii.md>), [Machine Learning, Security Attacks](<https://devfeed.tech/topics/machine-learning-security-attacks.md>), [Language models](<https://devfeed.tech/topics/language-models.md>), [telemetry](<https://devfeed.tech/topics/telemetry.md>), [Microsoft](<https://devfeed.tech/topics/microsoft.md>)

Tags: [ai-models](<https://devfeed.tech/tags/ai-models.md>), [ai-security](<https://devfeed.tech/tags/ai-security.md>), [ascii](<https://devfeed.tech/tags/ascii.md>), [microsoft](<https://devfeed.tech/tags/microsoft.md>), [phishing](<https://devfeed.tech/tags/phishing.md>), [security](<https://devfeed.tech/tags/security.md>), [social-engineering](<https://devfeed.tech/tags/social-engineering.md>), [telemetry](<https://devfeed.tech/tags/telemetry.md>)

## AI overview

Microsoft describes a phishing campaign that uses invisible Unicode tag characters to split lure words and evade email parsing. The technique, known as ASCII smuggling, was previously prominent in AI prompt-injection research because models can process hidden text that people cannot see.

## Source excerpt

Invisible Unicode characters popularized for hiding instructions from AI models are now being used to obfuscate words before email filters parse them. The post ASCII smuggling crosses over from AI prompt injection to phishing evasion appeared first on Microsoft Security Blog.