An intrusion detection system (IDS). An IDS which has been configured in accordance with the present invention can include a traffic sniffer for extracting network packets from passing network traffic; a traffic parser configured to extract individual data from defined packet fields of the network packets; and, a traffic logger configured to store individual packet fields of the network packets in a database. A vector builder can be configured to generate multi-dimensional vectors from selected features of the stored packet fields. Notably, at least one self-organizing clustering module can be configured to process the multi-dimensional vectors to produce a self-organized map of clusters. Subsequently, an anomaly detector can detect anomalous correlations between individual ones of the clusters in the self-organized map based upon at least one configurable correlation metric. Finally, a classifier can classify detected anomalous correlations as one of an alarm and normal behavior.