In network security, what is considered a 'false positive'?

A 'false positive' in network security refers to a situation where a detection system identifies a legitimate activity or object as a threat when, in fact, it is not harmful. This typically happens with security tools such as intrusion detection systems (IDS) or anti-virus software that generate alerts for suspected malicious activity based on certain signatures or heuristics.

When these systems trigger alerts for benign activities—such as normal traffic patterns or authorized user actions—this can lead to unnecessary investigations and wasted resources. Understanding false positives is crucial for security professionals, as a high rate of false positives can desensitize incident handlers to alerts and potentially cause them to overlook actual threats. This idea contrasts with other terms where legitimate access might be mistakenly blocked or threats go undetected, neither of which fits the definition of a false positive.