Microsoft says email spammers are adopting ASCII smuggling, an AI prompt injection tactic used to hide malicious instructions, to evade email platform filters (Dan Goodin/Ars Technica)

Microsoft reports that email spammers are employing ASCII smuggling—a prompt-injection technique originally used to conceal malicious instructions from AI models—to evade detection by email platform filters. The tactic leverages hidden ASCII characters to mask spam content, forcing security systems to miss the malicious payload.