Network Intrusion Detection System (NIDS)

This paper introduces the Network Intrusion Detection System (NIDS), which uses a suite of data mining techniques to automatically detect attacks against computer networks and systems. This paper focuses on two specific contributions: (i) an unsupervised anomaly detection technique that assigns a score to each network connection that reflects how anomalous the connection is, and (ii) an association pattern analysis based module that summarizes those network connections that are ranked highly anomalous by the anomaly detection module. Experimental results show that our anomaly detection techniques are successful in automatically detecting several intrusions that could not be identified using popular signature-based tools .Furthermore, given the very high volume of connections observed per unit time, association pattern based summarization of novel attacks is quite useful in enabling a security analyst to understand and characterize emerging threats.