Using Specification-Based Intrusion Detection for Automated Response

One of the most controversial issues in intrusion detection is automating responses to intrusions, which can provide a more efficient, quicker, and precise way to react to an attack in progress than a human. However, it comes with several disadvantages that can lead to a waste of resources, which has so far prevented wide acceptance of automated response-enabled systems. We feel that a structured approach to the problem is needed that will account for the above mentioned disadvantages. In this work, we briefly describe what has been done in the area before. Then we start addressing the problem by coupling automated response with specification-based, host-based intrusion detection. We describe the system map, and the map-based action cost model that give us the basis for deciding on response strategy. We also show the process of suspending the attack, and designing the optimal response strategy, even in the presence of uncertainty. Finally, we discuss the implementation issues, our experience with the early automated response agent prototype, the Automated Response Broker (ARB), and suggest topics for further research.