Mining Network Traffic with the k -Means Clustering Algorithm for Stepping-Stone Intrusion Detection

Intruders on the Internet usually launch network attacks through compromised hosts, called stepping stones, in order to reduce the chance of being detected. With stepping-stone intrusions, an attacker uses tools such as SSH to log in several compromised hosts remotely and create an interactive connection chain and then sends attacking packets to a target system. An effective method to detect such an intrusion is to estimate the length of a connection chain. In this paper, we develop an efficient algorithm to detect stepping-stone intrusion by mining network traffic using the k-means clustering. Existing approaches for connection-chainbased stepping-stone intrusion detection either are not effective or require a large number of TCP packets to be captured and processed and, thus, are not efficient. Our proposed detection algorithm can accurately determine the length of a connection chain without requiring a large number of TCP packets being captured and processed, so it is more efficient. Our proposed detection algorithm is also easier to implement than all existing approaches for stepping-stone intrusion detection. The effectiveness, correctness, and efficiency of our proposed detection algorithm are verified through well-designed network experiments.