Machine Learning for Detecting Brute Force Attacks at the Network Level

The tremendous growth in computer network and Internet usage, combined with the growing number of attacks makes network security a topic of serious concern. One of the most prevalent network attacks that can threaten computers connected to the network is brute force attack. In this work we investigate the use of machine learners for detecting brute force attacks (on the SSH protocol) at the network level. We base our approach on applying machine learning algorithms on a newly generated dataset based upon network flow data collected at the network level. Applying detection at the network level makes the detection approach more scalable. It also provides protection for the hosts who do not have their own protection. The new dataset consists of real-world network data collected from a production network. We use four different classifiers to build brute force attack detection models. The use of different classifiers facilitates a relatively comprehensive study on the effectiveness of machine learners in the detection of brute force attack on the SSH protocol at the network level. Empirical results show that the machine learners were quite successful in detecting the brute force attacks with a high detection rate and low false alarms. We also investigate the effectiveness of using ports as features during the learning process. We provide a detailed analysis of how the models built can change as a result of including or excluding port features.