title: Defending Against Advanced Persistent Threats Using Game-Theory.
abstract: Advanced persistent threats (APT) combine a variety of different attack forms ranging from social engineering to technical exploits. The diversity and usual stealthiness of APT turns them into a central problem of contemporary practical system security, since information on attacks, the current system status or the attacker's incentives is often vague, uncertain and in many cases even unavailable. Game theory is a natural approach to model the conflict between the attacker and the defender, and this work investigates a generalized class of matrix games as a risk mitigation tool for an advanced persistent threat (APT) defense. Unlike standard game and decision theory, our model is tailored to capture and handle the full uncertainty that is immanent to APTs, such as disagreement among qualitative expert risk assessments, unknown adversarial incentives and uncertainty about the current system state (in terms of how deeply the attacker may have penetrated into the system's protective shells already). Practically, game-theoretic APT models can be derived straightforwardly from topological vulnerability analysis, together with risk assessments as they are done in common risk management standards like the ISO 31000 family. Theoretically, these models come with different properties than classical game theoretic models, whose technical solution presented in this work may be of independent interest.
authors.affiliation: Universität Klagenfurt, Institute of Applied Informatics, Klagenfurt, Austria.
authors.forename: Stefan
authors.identifier: http://orcid.org/0000-0003-2821-2489
authors.initials: S
authors.lastname: Rass
authors.affiliation: Austrian Institute of Technology, Safety & Security Department, Klagenfurt, Austria.
authors.forename: Sandra
authors.initials: S
authors.lastname: König
authors.affiliation: Austrian Institute of Technology, Safety & Security Department, Klagenfurt, Austria.
authors.forename: Stefan
authors.initials: S
authors.lastname: Schauer
mesh_terms: D016494:Computer Security; D003199:Computer Systems; D003661:Decision Support Techniques; D005716:Game Theory; D006801:Humans; D008962:Models, Theoretical; D011336:Probability; D018570:Risk Assessment; D012308:Risk Management; D012984:Software; D013269:Stochastic Processes; D035501:Uncertainty