To find out the relationship among the data from the field of data mining association rule mining can be used for the creation of frequent item set.The famous and well known algorithm is that of Apriori Further clustering can also be used to make the cluster of the data. The classification method is also used in some cases if required
In addition to previous answer I would like to add following. Clustering and Classification Algorithm – Supervised (CCAS) is used for cyber attack detection. Moreover the Markov chain model of event transitions, artificial neural networks, statistical anomaly detection techniques (for example, Chi-Square Distance Monitoring method) are applied for cyber attack detection.