Identifying High Quality Carding Services in Underground Economy using Nonparametric Supervised Topic Model

Over the years, cybercriminals increasingly joined the underground economy to exchange malicious services for conducting data breaches crimes. As many service providers are rippers, most cybercriminals rely on a few high quality services. To this end, cybercriminals post customer reviews evaluating the purchase experience and the service quality. To identify high quality services, researchers face two major challenges – the cybercriminal-specific language and the scale of the underground economy. This study presents a text-mining-based system for identifying high quality services by analyzing customer reviews. A novel supervised topic model is designed to accommodate the heterogeneous and uncertain nature of customer reviews. We further designed a variational algorithm for model inference. Moreover, we collected real data from two underground economy forums for English-speaking and Russian-speaking cybercriminals as our research testbed. Our research contributes to the practice of understanding and mitigating underground economy by providing cybersecurity researchers and practitioners with actionable intelligence

Dealings on the Dark Web: An Examination of the Trust, Consumer Satisfaction, and the Efficacy of Interventions Against a Dark Web Cryptomarket

Abstract Objective. The overarching goal of this thesis is to better understand not only the network dynamics which undergird the function and operation of cryptomarkets but the nature of consumer satisfaction and trust on these platforms. More specifically, I endeavour to push the cryptomarket literature beyond its current theoretical and methodological limits by documenting the network structure of a cryptomarket, the factors which predicts for vendor trust, the efficacy of targeted strategies on the transactional network of a cryptomarket, and the dynamics which facilitate consumer satisfaction despite information asymmetry. Moreover, we also aim to test the generalizability of findings made in prior cryptomarket studies (Duxbury and Haynie, 2017; 2020; Norbutas, 2018). Methods. I realize the aims of this research by using a buyer-seller dataset from the Abraxas cryptomarket (Branwen et al., 2015). Given the differences between the topics and the research questions featured, this thesis employs a variety of methodological techniques. Chapter two uses a combination of descriptive network analysis, community detection analysis, statistical modelling, and trajectory modelling. Chapter three utilizes three text analytic strategies: descriptive text analysis, sentiment analysis, and textual feature extraction. Finally, chapter four employs sequential node deletion pursuant to six law enforcement strategies: lead k (degree centrality), eccentricity, unique items bought/sold, cumulative reputation score, total purchase price, and random targeting. Results. Social network analysis of the Abraxas cryptomarket revealed a large and diffuse network where the majority of buyers purchased from a small cohort of vendors. This theme of preferential selection of vendors on the part of buyers is repeated in other findings within this study. More generally, the Abraxas transactional network can then be viewed as set of transactional islands as opposed to a large, densely connected conglomeration of vendors and buyers. With regard buyer feedback, buyers are generally pleased with their transactions on Abraxas as long as the product arrives on time and is as advertised. In general, vendors have a relatively low bar to achieve when it comes to satisfying their customers. Based on the results of the sequential node deletion, random targeting was found to be ineffective across the five outcome measures, producing minimal and a slow disruptive effect. Finally, these strategies are based on a power law where a small percentage of deleted nodes is responsible for an outsized proportion of the disruptive impact. Conclusion. As with all applied research examining emergent phenomena, this thesis lends itself to a more refined understanding of dark web cryptomarkets. While the results and conclusions drawn from these results are not perfectly generalizable to all cryptomarkets, they should serve to inform law enforcement on the dynamics which undergird these markets. To this extent, a sombre consideration of trust, consumer satisfaction, and tactical effectiveness of interventions is a necessary step towards the development of more effective countermeasures against these illicit online marketplaces. For law enforcement to be more effective against cryptomarkets, it is advised that an evidence-based approach be taken

Epistemological Crisis in Ethical Governance and Constructing a New Islamic Episteme as an Ethical Theory: A Case of Institution of Hisbah

The research presented in this thesis explores the governance within Islamic thought in the case of the institution of hisbah as well as exploring the episteme that is the cause of the recognised and unrecognised incoherencies and inconsistencies in the theories, regulations, and laws associated to the institution of hisbah. The analysis is based on conducting an epistemological examination in moral philosophical dialect in relation to the historical regulative institution of hisbah. Institution of hisbah constitutes the focus of this research, because this institution was politically structured, theologically positioned and theoretically entrusted to maintain public law and order, with the objective of supervising the behaviour in society and market from an Islamic perspective by using Islamic legal theories within its own theoretical framework with the aim of subscribing good and forbidding evil. The analysis presented found that the institution of hisbah was subject to continuous institutional failures throughout its history. In advancing the analysis, the research deconstructs the theoretical framework upon which the institution of hisbah located its operations for the moral governance of the market and the society. The deconstruction of theoretical frameworks point to the use of Islamic legal theory and juristic subjectivity for judging the moral conduct of activities as the root cause of the problem. The study further deconstructed the Islamic legal theory along side exploring for the alternative episteme within the broader view of Islamic thought, given the diversity of philosophical standpoints on good and evil within Islamic discourse. However, the result of this exploration suggests that epistemological crisis embodies the whole of Islamic tradition, which pave the way to a rise in crisis in morality and crisis in legitimacy within the tradition, which resulted in institutional failures, such as the ones witnessed in the operations of institution of hisbah. The study further discovers that consequent to the crisis in the Islamic tradition, the key questions on good and evil, within the realm of governance can no longer be settled by using the historically established tradition’s epistemological sources, because within the current settings of tradition, there is insufficient or no method of enquiry, form of argumentation and episteme that can address the crises, or through which a solution for the crises can be derived. By using MacIntyre’s work as a conceptual structure, this research attempts to construct a new epistemological source that may address the crises by specifying a model justified through model-dependent realism with the objective of creating a new point of orientation through which reality and dichotomy of good and evil can be objectively understood, whilst safeguarding the life form of the fabric of belief that is central to the traditional Islamic thought. Such episteme can then be used as an ethical theory by the institution of hisbah for judging the moral conduct of activities in the market and society. The new episteme is constructed, while preserving the tradition’s consequential essence. The consequential essence is inferred down to morality based on objectiveness and universality, and away from public choice, along with the notion of survival as episteme for philosophical perspective and theological stance. The consequential essence of tradition is maintained by using objectivist ethics and environmental sustainability within the outlines of classic theories on sovereignty of internal and external realm, as a foundational framework to construct the proposed model of ‘objective subjectivism’ as a theory of normative ethics. This proposed episteme as an Islamic ethical theory asserts that standard of value is life and measure of value and purpose of life is sustainability, and through this notion good and evil can be objectively distinguished for each realm, and therefore institutionally subscribed or prohibited for that realm, thus providing a workable framework for the operations of hisbah. As a research methodology and model construction process, the research presented in this research utilises discursive reasoning to conduct an epistemological enquiry based on critical discourse analysis, which is ontologically justified by model-dependent realism and epistemologically framed under consequentialism