Copilot Cowork can silently exfiltrate M365 files via automated email and Teams messages
PromptArmor shows that Microsoft Copilot Cowork can leak files from SharePoint or OneDrive by injecting malicious skills that trigger automatic emails or Teams messages. These messages embed pre‑authenticated download links, allowing attackers to retrieve data when the user opens the message, highlighting inherent risks in agentic enterprise tools.