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 an additional layer of security 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 an anomaly or strange trend is detected that might indicate the presence of a threat. Large-scale examples of such characteristics include increased 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 can be flagged.
NBAD should be used in addition to conventional firewalls and applications for the detection of malware. Some vendors include NBA/NBAD components as part of their standard network security software suites.