Defending Against Advanced Persistent Threats using Game-Theory

TL;DR

This paper proposes a game-theoretic framework tailored for defending against advanced persistent threats (APTs), capturing uncertainties like attacker incentives and system state, and offers a new solution approach for these complex models.

Contribution

It introduces a generalized class of matrix games specifically designed to handle the uncertainties inherent in APT defense, extending classical game theory applications.

Findings

Model effectively captures APT uncertainties

Provides a novel solution method for complex game models

Framework integrates with existing risk assessment standards

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 APT defense. Unlike standard game and decision theory, our model is tailored to capture and handle the full uncertainty that is immanent to APT, 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.