While XR systems face many of the same cyber threats as traditional computing, the way users are warned in immersive environments must be particularly careful. Without timely and effective alerts, users may continue to interact with infected systems without knowing it, compromising their security, privacy, and trust. This is especially true for attacks like denial-of-service (DoS), which can silently degrade the XR experience by reducing frame rates, interfering with inputs, or overloading sensors. At SUN, we are building an early detection system that monitors subtle signs of attack in real-time and uses machine learning to identify anomalies. The goal is to protect users before performance is noticeably impacted, whether it’s a sudden drop-in frame rate or a delay in interaction. By responding early, the system can reduce the risk of causing damage. This is not only to protect users, but also to protect the environment.