Intrusion detection system (IDS) is a device or software application that monitors network or system activities for malicious activities or policy violations and produces reports to a management station. Unlike heuristics or fingerprint-based scanners, behavior blocking software integrates with the operating system of a host computer and monitors program behavior in real-time for malicious actions. The behavior blocking software then blocks potentially malicious actions before they have a chance to affect the system. The Behavior Blocker intercepts all files before they are loaded into memory and intercepts prefetching/caching attempts for those files. It calculates the hash of the executable at the point it attempts to load into the memory. It then compares this hash with the list of known / recognized applications that are on the Comodo safe list.