Microsoft Copilot: From Prompt Injection to Exfiltration of Personal Information

Microsoft 365 Copilot has a vulnerability that allows attackers to steal personal information like emails and MFA codes through a multi-step attack. The exploit uses prompt injection (tricking an AI by hiding malicious instructions in emails or documents), automatic tool invocation (making Copilot search for additional sensitive data without user permission), and ASCII smuggling (hiding data in invisible characters within clickable links) to extract and exfiltrate personal information.