Towards the Automated Detection of Unknown Malware on Live Systems

Abstract—In this paper, we propose a new system monitoring framework that can serve as an enabler for automated malware detection on live systems. Our approach takes advantage of the increased availability of hardware assisted virtualization capabilities of modern CPUs, and its basic novelty consists in launching a hypervisor layer on the live system without stopping and restarting it. This hypervisor runs at a higher privilege level than the OS itself, thus, it can be used to observe the behavior of the analyzed system in a transparent manner. For this purpose, we also propose a novel system call tracing method that is designed to be configurable in terms of transparency and granularity. I

MODELLING LOCATION REVEAL ATTACKS IN MOBILE SYSTEMS

We propose a novel approach for the modelling and discovery of location reveal attacks in mobile environments. Our approach is based on the theory of Communicating Sequential Processes (CSP). We demonstrate the power of our approach by analysing the MIPv4 protocol and by showing that it does not protect the location information of the mobile node appropriately. In order to solve this problem we specify which communications should be encrypted within MIPv4. The so specified protocols verify correctly in our CSP based model

IoT Malware Detection with Machine Learning

Embedded devices are increasingly connected to the Internet to provide new and innovative applications in many domains. However, these IoT devices can also contain security vulnerabilities, which allow attackers to compromise them using malware. We report on our recent work on using machine learning for efficient and effective malware detection on resource-constrained IoT devices

Building blocks for secure services:authenticated key transport and rational exchange protocols

This thesis is concerned with two security mechanisms: authenticated key transport and rational exchange protocols. These mechanisms are potential building blocks in the security architecture of a range of different services. Authenticated key transport protocols are used to build secure channels between entities, which protect their communications against eaves-dropping and alteration by an outside attacker. In contrast, rational exchange protocols can be used to protect the entities involved in an exchange transaction from each other. This is important, because often the entities do not trust each other, and both fear that the other will gain an advantage by misbehaving. Rational exchange protocols alleviate this problem by ensuring that a misbehaving party cannot gain any advantages. This means that misbehavior becomes uninteresting and it should happen only rarely. The thesis is focused on the construction of formal models for authenticated key transport and rational exchange protocols. In the first part of the thesis, we propose a formal model for key transport protocols, which is based on a logic of belief. Building on this model, we also propose an original systematic protocol construction approach. The main idea is that we reverse some implications that can be derived from the axioms of the logic, and turn them into synthesis rules. The synthesis rules can be used to construct a protocol and to derive a set of assumptions starting from a set of goals. The main advantage is that the resulting protocol is guaranteed to be correct in the sense that all the specified goals can be derived from the protocol and the assumptions using the underlying logic. Another important advantage is that all the assumptions upon which the correctness of the protocol depends are made explicit. The protocol obtained in the synthesis process is an abstract protocol, in which idealized messages that contain logical formulae are sent on channels with various access properties. The abstract protocol can then be implemented in several ways by replacing the idealized messages and the channels with appropriate bit strings and cryptographic primitives, respectively. We illustrate the usage of the logic and the synthesis rules through an example: We analyze an authenticated key transport protocol proposed in the literature, identify several weaknesses, show how these can be exploited by various attacks, and finally, we redesign the protocol using the proposed systematic approach. We obtain a protocol that resists against the presented attacks, and in addition, it is simpler than the original one. In the second part of the thesis, we propose an original formal model for exchange protocols, which is based on game theory. In this model, an exchange protocol is represented as a set of strategies in a game played by the protocol parties and the network that they use to communicate with each other. We give formal definitions for various properties of exchange protocols in this model, including rationality and fairness. Most importantly, rationality is defined in terms of a Nash equilibrium in the protocol game. The model and the formal definitions allow us to rigorously study the relationship between rational exchange and fair exchange, and to prove that fairness implies rationality (given that the protocol satisfies some further usual properties), but the reverse is not true in general. We illustrate how the formal model can be used for rigorous verification of existing protocols by analyzing two exchange protocols, and formally proving that they satisfy the definition of rational exchange. We also present an original application of rational exchange: We show how the concept of rationality can be used to improve a family of micropayment schemes with respect to fairness without substantial loss in efficiency. Finally, in the third part of the thesis, we extend the concept of rational exchange, and describe how similar ideas can be used to stimulate the nodes of a self-organizing ad hoc network for cooperation. More precisely, we propose an original approach to stimulate the nodes for packet forwarding. Like in rational exchange protocols, our design does not guarantee that a node cannot deny packet forwarding, but it ensures that it cannot gain any advantages by doing so. We analyze the proposed solution analytically and by means of simulation

Formal verification of secure ad-hoc network routing protocols using deductive model-checking

Ad-hoc networks do not rely on a pre-installed infrastructure, but they are formed by end-user devices in a self-organized manner. A consequence of this principle is that end-user devices must also perform routing functions. However, end-user devices can easily be compromised, and they may not follow the routing protocol faithfully. Such compromised and misbehaving nodes can disrupt routing, and hence, disable the operation of the network. In order to cope with this problem, several secured routing protocols have been proposed for ad-hoc networks. However, many of them have design flaws that still make them vulnerable to attacks mounted by compromised nodes. In this paper, we propose a formal verification method for secure ad-hoc network routing protocols that helps increasing the confidence in a protocol by providing an analysis framework that is more systematic, and hence, less error-prone than the informal analysis. Our approach is based on a new process calculus that we specifically developed for secure ad-hoc network routing protocols and a deductive proof technique. The novelty of this approach is that contrary to prior attempts to formal verification of secure ad-hoc network routing protocols, our verification method can be made fully automated

Game-theoretic Robustness of Many-to-one Networks

In this paper, we study the robustness of networks that are characterized by many-to-one communications (e.g., access networks and sensor networks) in a game-theoretic model. More specifically, we model the interactions between a network operator and an adversary as a two player zero-sum game, where the network operator chooses a spanning tree in the network, the adversary chooses an edge to be removed from the network, and the adversary’s payoff is proportional to the number of nodes that can no longer reach a designated node through the spanning tree. We show that the payoff in every Nash equilibrium of the game is equal to the reciprocal of the persistence of the network. We describe optimal adversarial and operator strategies and give efficient, polynomial-time algorithms to compute optimal strategies. We also generalize our game model to include varying node weights, as well as attacks against nodes