Dynamic adversarial mining - effectively applying machine learning in adversarial non-stationary environments.

While understanding of machine learning and data mining is still in its budding stages, the engineering applications of the same has found immense acceptance and success. Cybersecurity applications such as intrusion detection systems, spam filtering, and CAPTCHA authentication, have all begun adopting machine learning as a viable technique to deal with large scale adversarial activity. However, the naive usage of machine learning in an adversarial setting is prone to reverse engineering and evasion attacks, as most of these techniques were designed primarily for a static setting. The security domain is a dynamic landscape, with an ongoing never ending arms race between the system designer and the attackers. Any solution designed for such a domain needs to take into account an active adversary and needs to evolve over time, in the face of emerging threats. We term this as the ‘Dynamic Adversarial Mining’ problem, and the presented work provides the foundation for this new interdisciplinary area of research, at the crossroads of Machine Learning, Cybersecurity, and Streaming Data Mining. We start with a white hat analysis of the vulnerabilities of classification systems to exploratory attack. The proposed ‘Seed-Explore-Exploit’ framework provides characterization and modeling of attacks, ranging from simple random evasion attacks to sophisticated reverse engineering. It is observed that, even systems having prediction accuracy close to 100%, can be easily evaded with more than 90% precision. This evasion can be performed without any information about the underlying classifier, training dataset, or the domain of application. Attacks on machine learning systems cause the data to exhibit non stationarity (i.e., the training and the testing data have different distributions). It is necessary to detect these changes in distribution, called concept drift, as they could cause the prediction performance of the model to degrade over time. However, the detection cannot overly rely on labeled data to compute performance explicitly and monitor a drop, as labeling is expensive and time consuming, and at times may not be a possibility altogether. As such, we propose the ‘Margin Density Drift Detection (MD3)’ algorithm, which can reliably detect concept drift from unlabeled data only. MD3 provides high detection accuracy with a low false alarm rate, making it suitable for cybersecurity applications; where excessive false alarms are expensive and can lead to loss of trust in the warning system. Additionally, MD3 is designed as a classifier independent and streaming algorithm for usage in a variety of continuous never-ending learning systems. We then propose a ‘Dynamic Adversarial Mining’ based learning framework, for learning in non-stationary and adversarial environments, which provides ‘security by design’. The proposed ‘Predict-Detect’ classifier framework, aims to provide: robustness against attacks, ease of attack detection using unlabeled data, and swift recovery from attacks. Ideas of feature hiding and obfuscation of feature importance are proposed as strategies to enhance the learning framework\u27s security. Metrics for evaluating the dynamic security of a system and recover-ability after an attack are introduced to provide a practical way of measuring efficacy of dynamic security strategies. The framework is developed as a streaming data methodology, capable of continually functioning with limited supervision and effectively responding to adversarial dynamics. The developed ideas, methodology, algorithms, and experimental analysis, aim to provide a foundation for future work in the area of ‘Dynamic Adversarial Mining’, wherein a holistic approach to machine learning based security is motivated

Three Decades of Deception Techniques in Active Cyber Defense -- Retrospect and Outlook

Deception techniques have been widely seen as a game changer in cyber defense. In this paper, we review representative techniques in honeypots, honeytokens, and moving target defense, spanning from the late 1980s to the year 2021. Techniques from these three domains complement with each other and may be leveraged to build a holistic deception based defense. However, to the best of our knowledge, there has not been a work that provides a systematic retrospect of these three domains all together and investigates their integrated usage for orchestrated deceptions. Our paper aims to fill this gap. By utilizing a tailored cyber kill chain model which can reflect the current threat landscape and a four-layer deception stack, a two-dimensional taxonomy is developed, based on which the deception techniques are classified. The taxonomy literally answers which phases of a cyber attack campaign the techniques can disrupt and which layers of the deception stack they belong to. Cyber defenders may use the taxonomy as a reference to design an organized and comprehensive deception plan, or to prioritize deception efforts for a budget conscious solution. We also discuss two important points for achieving active and resilient cyber defense, namely deception in depth and deception lifecycle, where several notable proposals are illustrated. Finally, some outlooks on future research directions are presented, including dynamic integration of different deception techniques, quantified deception effects and deception operation cost, hardware-supported deception techniques, as well as techniques developed based on better understanding of the human element.Comment: 19 page

Reeling in Big Phish with a Deep MD5 Net

Phishing continues to grow as phishers discover new exploits and attack vectors for hosting malicious content; the traditional response using takedowns and blacklists does not appear to impede phishers significantly. A handful of law enforcement projects — for example the FBI\u27s Digital PhishNet and the Internet Crime and Complaint Center (ic3.gov) — have demonstrated that they can collect phishing data in substantial volumes, but these collections have not yet resulted in a significant decline in criminal phishing activity. In this paper, a new system is demonstrated for prioritizing investigative resources to help reduce the time and effort expended examining this particular form of online criminal activity. This research presents a means to correlate phishing websites by showing that certain websites are created by the same phishing kit. Such kits contain the content files needed to create the counterfeit website and often contain additional clues to the identity of the creators. A clustering algorithm is presented that uses collected phishing kits to establish clusters of related phishing websites. The ability to correlate websites provides law enforcement or other potential stakeholders with a means for prioritizing the allocation of limited investigative resources by identifying frequently repeating phishing offenders

МОДЕЛЬ АНАЛІЗУ СТРАТЕГІЙ ПРИ ДИНАМІЧНІЙ ВЗАЄМОДІЇ УЧАСНИКІВ ФІШИНГОВИХ АТАК

The paper proposes an approach that allows countering attacks on cryptocurrency exchanges and their clients. This approach is formalized in the form of a synthesis of a dynamic model of resistance to phishing attacks and a perceptron model in the form of the simplest artificial neural network. The dynamics of the confrontation are determined by a system of differential equations that determines the change in the states of the victim of phishing attacks and the attacker who organizes such attacks. This allows to find optimal strategies for opposing parties within the scheme of a bilinear differential game with complete information. The solution of the game allows you to determine payment matrices, which are elements of the training set for artificial neural networks. The synthesis of such models will make it possible to find a strategy to resist phishing with a sufficient degree of accuracy. This will minimize the losses of the victim of phishing attacks and of the protection side, which provides a secure system of communication with clients of the cryptocurrency exchange. The proposed neuro-game approach makes it possible to effectively forecast the process of countering phishing in the context of costs for parties using different strategies.У роботі запропоновано підхід, що дозволяє здійснювати протидію атакам на криптовалютні біржі та їх клієнтів. Даний підхід формалізований у вигляді синтезу динамічної моделі протистояння фішинговим атакам та моделі персептрона у вигляді найпростішої штучної нейронної мережі. Динаміка протистояння визначається системою диференціальних рівнянь, що визначає зміну станів жертви фішингових атак та зловмисника, який організовує такі атаки. Це дозволяє знайти оптимальні стратегії протистояння сторін у рамках схеми білінійної диференціальної гри з повною інформацією. Рішення гри дозволяє визначити платіжні матриці, що є елементами навчального набору для штучних нейронних мереж. Синтез таких моделей дасть можливість із достатнім ступенем точності знаходити стратегію протистояння фішингу. Це дозволить мінімізувати втрати жертви фішингових атак та сторони захисту, яка забезпечує безпечну систему спілкування із клієнтами криптовалютної біржі. Запропонований нейро-ігровий підхід дозволяє ефективно здійснювати прогноз процесу протистояння фішингу у контексті витрат для сторін, що використовують різні стратегії

Spear Phishing Attack Detection

This thesis addresses the problem of identifying email spear phishing attacks, which are indicative of cyber espionage. Spear phishing consists of targeted emails sent to entice a victim to open a malicious file attachment or click on a malicious link that leads to a compromise of their computer. Current detection methods fail to detect emails of this kind consistently. The SPEar phishing Attack Detection system (SPEAD) is developed to analyze all incoming emails on a network for the presence of spear phishing attacks. SPEAD analyzes the following file types: Windows Portable Executable and Common Object File Format (PE/COFF), Adobe Reader, and Microsoft Excel, Word, and PowerPoint. SPEAD\u27s malware detection accuracy is compared against five commercially-available email anti-virus solutions. Finally, this research quantifies the time required to perform this detection with email traffic loads emulating an Air Force base network. Results show that SPEAD outperforms the anti-virus products in PE/COFF malware detection with an overall accuracy of 99.68% and an accuracy of 98.2% where new malware is involved. Additionally, SPEAD is comparable to the anti-virus products when it comes to the detection of new Adobe Reader malware with a rate of 88.79%. Ultimately, SPEAD demonstrates a strong tendency to focus its detection on new malware, which is a rare and desirable trait. Finally, after less than 4 minutes of sustained maximum email throughput, SPEAD\u27s non-optimized configuration exhibits one-hour delays in processing files and links

Rational Multiparty Computation

The field of rational cryptography considers the design of cryptographic protocols in the presence of rational agents seeking to maximize local utility functions. This departs from the standard secure multiparty computation setting, where players are assumed to be either honest or malicious. ^ We detail the construction of both a two-party and a multiparty game theoretic framework for constructing rational cryptographic protocols. Our framework specifies the utility function assumptions necessary to realize the privacy, correctness, and fairness guarantees for protocols. We demonstrate that our framework correctly models cryptographic protocols, such as rational secret sharing, where existing work considers equilibrium concepts that yield unreasonable equilibria. Similarly, we demonstrate that cryptography may be applied to the game theoretic domain, constructing an auction market not realizable in the original formulation. Additionally, we demonstrate that modeling players as rational agents allows us to design a protocol that destabilizes coalitions. Thus, we establish a mutual benefit from combining the two fields, while demonstrating the applicability of our framework to real-world market environments.^ We also give an application of game theory to adversarial interactions where cryptography is not necessary. Specifically, we consider adversarial machine learning, where the adversary is rational and reacts to the presence of a data miner. We give a general extension to classification algorithms that returns greater expected utility for the data miner than existing classification methods