Biblio

Most of the recent high-profile attacks targeting cyber-physical systems (CPS) started with lengthy reconnaissance periods that enabled attackers to gain in-depth understanding of the victim’s environment. To simulate these stealthy attacks, several covert channel tools have been published and proven effective in their ability to blend into existing CPS communication streams and have the capability for data exfiltration and command injection.In this paper, we report a novel machine learning feature engineering and data processing pipeline for the detection of covert channel attacks on CPS systems with real-time detection throughput. The system also operates at the network layer without requiring physical system domain-specific state modeling, such as voltage levels in a power generation system. We not only demonstrate the effectiveness of using TCP payload entropy as engineered features and the technique of grouping information into network flows, but also pitch the proposed detector against scenarios employing advanced evasion tactics, and still achieve above 99% detection performance.

Software Defined Networking (SDN) has changed the way of designing and managing networks through programmability. However, programmability also introduces security threats. In this work we address the issue of malicious hosts running malicious applications that bypass the standard SDN based detection mechanisms. The SDN security system we are proposing periodically monitors the system calls utilization of the different SDN applications installed, learns from past system behavior using machine learning classifiers, and thus accurately detects the existence of an unusual activity or a malicious application.