Network behavior anomaly detection (NBAD) is the continuous monitoring of a proprietary network for unusual events or trends. NBAD is an integral part of network behavior analysis (NBA), which offers security in addition to that provided by traditional anti-threat applications such as firewalls, antivirus software and spyware-detection software.
An NBAD program tracks critical network characteristics in real time and generates an alarm if a strange event or trend is detected that could indicate the presence of a threat. Large-scale examples of such characteristics include traffic volume, bandwidth use and protocol use.
An NBAD program can also monitor the behavior of individual network subscribers. In order for NBAD to be optimally effective, a baseline of normal network or user behavior must be established over a period of time. Once certain parameters have been defined as normal, any departure from one or more of them is flagged as anomalous.
NBAD should be used in addition to conventional firewalls and applications for the detection of malware. Some vendors have begun to recognize this fact by including NBA/NBAD programs as integral parts of their network security packages.