Biblio

In the ever evolving Internet threat landscape, Distributed Denial-of-Service (DDoS) attacks remain a popular means to invoke service disruption. DDoS attacks, however, have evolved to become a tool of deceit, providing a smokescreen or distraction while some other underlying attack takes place, such as data exfiltration. Knowing the intent of a DDoS, and detecting underlying attacks which may be present concurrently with it, is a challenging problem. An entity whose network is under a DDoS attack may not have the support personnel to both actively fight a DDoS and try to mitigate underlying attacks. Therefore, any system that can detect such underlying attacks should do so only with a high degree of confidence. Previous work utilizing flow aggregation techniques with multi-class anomaly detection showed promise in both DDoS detection and detecting underlying attacks ongoing during an active DDoS attack. In this work, we head in the opposite direction, utilizing flow segmentation and concurrent flow feature aggregation, with the primary goal of greatly reduced detection times of both DDoS and underlying attacks. Using the same multi-class anomaly detection approach, we show greatly improved detection times with promising detection performance.

Advanced Persistent Threats (APTs) refer to sophisticated, prolonged and multi-step attacks, planned and executed by skilled adversaries targeting government and enterprise networks. Attack graphs' topologies can be leveraged to detect, explain and visualize the progress of such attacks. However, due to the abundance of false-positives, such graphs are usually overwhelmingly large and difficult for an analyst to understand. Graph partitioning refers to the problem of reducing the graph of alerts to a set of smaller incidents that are easier for an analyst to process and better represent the actual attack plan. Existing approaches are oblivious to the security-context of the problem at hand and result in graphs which, while smaller, make little sense from a security perspective. In this paper, we propose an optimization approach allowing us to generate security-aware partitions, utilizing aspects such as the kill chain progression, number of assets involved, as well as the size of the graph. Using real-world datasets, the results show that our approach produces graphs that are better at capturing the underlying attack compared to state-of-the-art approaches and are easier for the analyst to understand.