Abstract
Unknown security attacks, or zero-day attacks, exploit unknown or undisclosed vulnerabilities and can cause devastating damage. We approach the problem from an intrusion response system's point of view, which deploys responses to contain an ongoing attack. However, the escalation pattern, commonly represented as an attack graph, is not known a priori for a zero-day attack. Hence, current IRS can only provide ineffective or drastic responses. We present an IRS called ADEPTS that "conceptualizes" nodes in an attack graph, whereby they are generalized based on the object-oriented hierachy for components and alerts. This is done based on our insight that high level manifestations of unknown attacks bear similarity with those of previously seen attacks. Thus, ADEPTS can find similarities between attack graphs after they have been conceptualized to an appropriate level. Then ADEPTS performs Bayesian inference to determine which components have been affected and determines the optimal response combination. We evaluate ADEPTS by injecting real multi-stage attacks scenarios, not present in its knowledge base, and compare the system survivabilitiy to our prior IRS.
Keywords
irs, intrusion detection, intrusion response, ADEPTS