Microsoft on Monday launched new security features, including Guardian Agents, to protect enterprises from the growing threat of AI agents. Microsoft CEO Satya Nadella and security business head Hayete Gallot warned that frontier models are untrustworthy because they are unpredictable and can be given access to sensitive data and the ability to perform critical operations, effectively acting as "insider threats." Microsoft also added agent detection capabilities to Microsoft Defender and limited agent access to data and dynamically adjusted permissions.