Software obfuscation is a protection technique for making code unintelligible to automated program comprehension and analysis tools. It works by performing semantic preserving transformations such that the difficulty of automatically extracting the computational logic out of code is increased. Obfuscating transforms in existing literature have been designed with the ambitious goal of being resilient against all possible reverse engineering attacks. Even though some of the constructions are based on intractable computational problems, we do not know, in practice, how to generate hard instances of obfuscated problems such that all forms of program analyses would fail. In this thesis, we address the problem of software protection by developing a weaker notion of obfuscation under which it is not required to guarantee an absolute blackbox security. Using this notion, we develop provably-correct obfuscating transforms using dependencies existing within program structures and indeterminacies in communication characteristics between programs in a distributed computing environment. We show how several well known static analysis tools can be used for reverse engineering obfuscating transforms that derive resilience from computationally hard problems. In particular, we restrict ourselves to one common and potent static analysis tool, the static slicer, and use it as our attack tool. We show the use of derived software engineering metrics to indicate the degree of success or failure of a slicer attack on a piece of obfuscated code. We address the issue of proving correctness of obfuscating transforms by adapting existing proof techniques for functional program refinement and communicating sequential processes. The results of this thesis could be used for future work in two ways: first, future researchers may extend our proposed techniques to design obfuscations using a wider range of dependencies that exist between dynamic program structures. Our restricted attack model using one static analysis tool can also be relaxed and obfuscations capable of withstanding a broader class of static and dynamic analysis attacks could be developed based on the same principles. Secondly, our obfuscatory strength evaluation techniques could guide anti-malware researchers in the development of tools to detect obfuscated strains of polymorphic viruses. / Whole document restricted, but available by request, use the feedback form to request access.

Software obfuscation is a protection technique for making code unintelligible to automated program comprehension and analysis tools. It works by performing semantic preserving transformations such that the difficulty of automatically extracting the computational logic out of code is increased. Obfuscating transforms in existing literature have been designed with the ambitious goal of being resilient against all possible reverse engineering attacks. Even though some of the constructions are based on intractable computational problems, we do not know, in practice, how to generate hard instances of obfuscated problems such that all forms of program analyses would fail. In this thesis, we address the problem of software protection by developing a weaker notion of obfuscation under which it is not required to guarantee an absolute blackbox security. Using this notion, we develop provably-correct obfuscating transforms using dependencies existing within program structures and indeterminacies in communication characteristics between programs in a distributed computing environment. We show how several well known static analysis tools can be used for reverse engineering obfuscating transforms that derive resilience from computationally hard problems. In particular, we restrict ourselves to one common and potent static analysis tool, the static slicer, and use it as our attack tool. We show the use of derived software engineering metrics to indicate the degree of success or failure of a slicer attack on a piece of obfuscated code. We address the issue of proving correctness of obfuscating transforms by adapting existing proof techniques for functional program refinement and communicating sequential processes. The results of this thesis could be used for future work in two ways: first, future researchers may extend our proposed techniques to design obfuscations using a wider range of dependencies that exist between dynamic program structures. Our restricted attack model using one static analysis tool can also be relaxed and obfuscations capable of withstanding a broader class of static and dynamic analysis attacks could be developed based on the same principles. Secondly, our obfuscatory strength evaluation techniques could guide anti-malware researchers in the development of tools to detect obfuscated strains of polymorphic viruses. / Whole document restricted, but available by request, use the feedback form to request access.

Orientador: Paulo Lício de Geus / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Computação / Made available in DSpace on 2018-08-16T05:27:31Z (GMT). No. of bitstreams: 1 Cavalcante_GabrielDieterich_M.pdf: 3073328 bytes, checksum: aeb145421a7f9c0c3d3ac872eb9ac054 (MD5) Previous issue date: 2010 / Resumo: Existe uma grande quantidade de configurações presentes em sistemas atuais e gerir essas configurações é um trabalho árduo para qualquer administrador de sistema. Inúmeras configurações podem ser definidas para uma só máquina e as combinações entre elas implicam de forma significativa no seu desempenho. A partir do momento que um sistema em pleno funcionamento pára de funcionar, algo em sua estrutura pode ter mudado. Este cenário é comum no processo de desenvolvimento de software onde o código fonte pode deixar de compilar ou ainda uma funcionalidade pode se perder. Controladores de versão são usados para reverter o estado do código para uma data anterior, solucionando o problema. Verificadores de Integridade são utilizados para detectar estas mudanças, porém não possuem mecanismos específicos para recuperação. Este estudo propõe e implementa uma arquitetura integrada que combina verificação de integridade e mecanismos de recuperação. Foram executados testes para determinar a sobrecarga total deste método, além de estudos de caso para verificar a sua eficiência de recuperação / Abstract: Current computer systems have a huge number of configurations that are hard to manage. The combinations of system configurations can impact on performance and behavior. From the moment that a system stops working correctly it is remarkable that something has changed. That is in common in software development, where changes made by the programmer may result in some features no longer working or the project not compiling anymore. Revision control systems can recover a previous state of the source code through revision mechanisms. Integrity checking is used to catch file modifications, however this technique does nothing toward recovering those files. This study proposes and implements an integrated architecture that combines integrity checking and restoring mechanisms. Tests were executed in order to measure the load imposed by the solution. In addition, analysis of three case studies shows the efficiency of the adopted solution / Mestrado / Segurança de Computadores

Orientadores: Mario Jino, Paulo Licio de Geus / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-21T16:40:48Z (GMT). No. of bitstreams: 1 Gregio_AndreRicardoAbed_D.pdf: 5158672 bytes, checksum: 12a24da95543bac78fd3f047f7415314 (MD5) Previous issue date: 2012 / Resumo: Ataques envolvendo programas maliciosos (malware) s~ao a grande ameaça atual _a segurança de sistemas. Assim, a motivação desta tese _e estudar o comportamento de malware e como este pode ser utilizado para fins de defesa. O principal mecanismo utilizado para defesa contra malware _e o antivírus (AV). Embora seu propósito seja detectar (e remover) programas maliciosos de máquinas infectadas, os resultados desta detecção provêem, para usuários e analistas, informações insuficientes sobre o processo de infecção realizado pelo malware. Além disso, não há um padrão de esquema de nomenclatura para atribuir, de maneira consistente, nomes de identificação para exemplares de malware detectados, tornando difícil a sua classificação. De modo a prover um esquema de nomenclatura para malware e melhorar a qualidade dos resultados produzidos por sistemas de análise dinâmica de malware, propõe-se, nesta tese, uma taxonomia de malware com base nos comportamentos potencialmente perigosos observados durante vários anos de análise de exemplares encontrados em campo. A meta principal desta taxonomia _e ser clara, de simples manutenção e extensão, e englobar tipos gerais de malware (worms, bots, spyware). A taxonomia proposta introduz quatro classes e seus respectivos comportamentos de alto nível, os quais representam atividades potencialmente perigosas. Para avaliá-la, foram utilizados mais de 12 mil exemplares únicos de malware pertencentes a diferentes classes (atribuídas por antivírus). Outras contribuições provenientes desta tese incluem um breve histórico dos programas maliciosos e um levantamento das taxonomias que tratam de tipos específicos de malware; o desenvolvimento de um sistema de análise dinâmica para extrair pefis comportamentais de malware; a especializa- _c~ao da taxonomia para lidar com exemplares de malware que roubam informações (stealers), conhecidos como bankers, a implementação de ferramentas de visualização para interagir com traços de execução de malware e, finalmente, a introdução de uma técnica de agrupamento baseada nos valores escritos por malware na memória e nos registradores / Abstract: Attacks involving malicious software (malware) are the major current threats to systems security. The motivation behind this thesis is to study malware behavior with that purpose. The main mechanism used for defending against malware is the antivirus (AV) tool. Although the purpose of an AV is to detect (and remove) malicious programs from infected machines, this detection usually provides insufficient information for users and analysts regarding the malware infection process. Furthermore, there is no standard naming scheme for consistently labeling detected malware, making the malware classification process harder. To provide a meaningful naming scheme, as well as to improve the quality of results produced by dynamic analysis systems, we propose a malware taxonomy based on potentially dangerous behaviors observed during several years of analysis of malware found in the wild. The main goal of the taxonomy is, in addition to being simple to understand, extend and maintain, to embrace general types of malware (e.g., worms, bots, spyware). Our behavior-centric malware taxonomy introduces four classes and their respective high-level behaviors that represent potentially dangerous activities. We applied our taxonomy to more than 12 thousand unique malware samples from different classes (assigned by AV scanners) to show that it is useful to better understand malware infections and to aid in malware-related incident response procedures. Other contributions of our work are: a brief history of malware and a survey of taxonomies that address specific malware types; a dynamic analysis system to extract behavioral profiles from malware; specialization of our taxonomy to handle information stealers known as bankers; proposal of visualization tools to interact with malware execution traces and, finally, a clustering technique based on values that malware writes into memory or registers / Doutorado / Engenharia de Computação / Doutor em Engenharia Elétrica

This thesis presents the developed taxonomy of the security threats in agent-based distributed systems. Based on this taxonomy, a set of theories is developed to facilitate analyzng the security threats of the mobile-agent systems. We propose the idea of using the developed security risk graph to model the system's vulnerabilties.

With the extreme growth in third party cloud applications, increased exposure of applications to the internet, and the impact of successful breaches, improving the security of software being produced is imperative. Static analysis tools can alert to quality and security vulnerabilities of an application; however, they present developers and analysts with a high rate of false positives and unactionable alerts. This problem may lead to the loss of confidence in the scanning tools, possibly resulting in the tools not being used. The discontinued use of these tools may increase the likelihood of insecure software being released into production. Insecure software can be successfully attacked resulting in the compromise of one or several information security principles such as confidentiality, availability, and integrity. Feature selection methods have the potential to improve the classification of static analysis alerts and thereby reduce the false positive rates. Thus, the goal of this research effort was to improve the classification of static analysis alerts by proposing and testing a novel method leveraging feature selection. The proposed model was developed and subsequently tested on three open source PHP applications spanning several years. The results were compared to a classification model utilizing all features to gauge the classification improvement of the feature selection model. The model presented did result in the improved classification accuracy and reduction of the false positive rate on a reduced feature set. This work contributes a real-world static analysis dataset based upon three open source PHP applications. It also enhanced an existing data set generation framework to include additional predictive software features. However, the main contribution is a feature selection methodology that may be used to discover optimal feature sets that increase the classification accuracy of static analysis alerts.

<p>This thesis presents research in the field of secure<br />software engineering. Two methods are<br />developed that, when combined, facilitate the<br />integration of software security design analysis<br />into the agile development workflow. The first<br />method is a training framework for creating<br />workshops aimed at teaching software engineers<br />on how to perform security design analysis. The<br />second method is a process that expands on the<br />security design analysis method to facilitate better<br />integration with the needs of the organization. The<br />first method is evaluated through a controlled<br />experiment, while the second method is evaluated<br />through comparative analysis and case study<br />analysis, where the process is tailored and<br />implemented for two different software vendors.</p> / <p>U sklopu disertacije izvr&scaron;eno je istraživanje u<br />oblasti razvoja bezbednog softvera. Razvijene su<br />dve metode koje zajedno omogućuju integraciju<br />bezbednosne analize dizajna softvera u proces<br />agilnog razvoja. Prvi metod predstavlja radni okvir<br />za konstruisanje radionica čija svrha je obuka<br />inženjera softvera kako da sprovode bezbednosnu<br />analizu dizajna. Drugi metod je proces koji<br />pro&scaron;iruje metod bezbednosne analize dizajna<br />kako bi podržao bolju integraciju spram potreba<br />organizacije. Prvi metod je evaluiran kroz<br />kontrolisan eksperiment, dok je drugi metod<br />evaluiran upotrebom komparativne analize i<br />analize studija slučaja, gde je proces<br />implementiran u kontekstu dve organizacije koje<br />se bave razvojem softvera.</p>

In recent years, companies and organizations have increasingly integrated software security testing into the software development life cycle using DevOps practices. The current integration approach introduces multiple challenges in an information technology environment that consists of a large number of software development projects and multiple software security testing tools. This thesis aims to address these challenges by proposing a microservice-based framework to unify application security testing. The thesis first identifies the challenges, then proposes a design for a framework based on relevant literature and common characteristics of application security testing tools. The main components of the proposed framework are implemented and evaluated. The evaluation result shows that the framework offers many benefits: more secure credential management process, reduced execution time for Continuous Integration (CI) pipelines, and more efficient project onboarding and management. Furthermore, the integration of the proposed framework does not introduce major security threats to the current environment. / Under de senaste åren har företag och organisationer i allt högre grad integrerat testning av programvarusäkerhet i livscykeln för programvaruutveckling med hjälp av DevOps-metoder. Den nuvarande integrationsmetoden medför flera utmaningar i en informationsteknisk miljö som består av ett stort antal programvaruutvecklingsprojekt och flera verktyg för testning av programvarusäkerhet. Detta examensarbete syftar till att ta itu med dessa utmaningar genom att föreslå en mikrotjänstbaserat ramverk för enhetlig testning av programsäkerhet. I arbetet identifieras först utmaningarna och därefter föreslås en konstruktion baserad på relevant litteratur och gemensamma egenskaper hos verktyg för testning av applikationssäkerhet. De viktigaste komponenterna i det föreslagna ramverket implementeras och utvärderas. Utvärderingsresultatet visar att ramverket erbjuder många fördelar: säkrare process för hantering av autentiseringsuppgifter, kortare genomförandetid för Continuous Integration (CI)-pipelines och effektivare projektstart och -hantering. Dessutom medför integrationen av det föreslagna ramverket inga större säkerhetshot i den nuvarande miljön.

Software security for agile methods, particularly for those designed for individual developers, is still a major concern. With most software products deployed over the Internet, security as a key component of software quality has become a major problem. In addressing this problem, this research proposes a solo software development methodology (SSDM) that uses as minimum resources as possible, at the same time conforming to the best practice for delivering secure and high-quality software products. Agile methods have excelled on delivering timely and quality software. At the same time research also shows that most agile methods do not address the problem of security in the developed software. A metasynthesis of SSDMs conducted in this thesis confirmed the lack practices that promote security in the developed software product. On the other hand, some researchers have demonstrated the feasibility of incorporating existing lightweight security practices into agile methods. This research uses Design Science Research (DSR) to build, demonstrate and evaluate a lightweight SSDM. Using an algorithm adapted for the purpose, the research systematically integrates lightweight security and quality practices to produce an agile secure-solo software development methodology (Secure-SSDM). A multiple-case study in an academic and industry setting is conducted to demonstrate and evaluate the utility of the methodology. This demonstration and evaluation thereof, indicates the applicability of the methodology in building high-quality and secure software products. Theoretical evaluation of the agility of the Secure-SSDM using the four-dimensional analytical tool (4-DAT) shows satisfactory compliance of the methodology with agile principles. The main contributions in this thesis are: the Secure-SSDM, which entails description of the concepts, modelling languages, stages, tasks, tools and techniques; generation of a quality theory on practices that promote quality in a solo software development environment; adaptation of Keramati and Mirian-Hosseinabadi’s algorithm for the purposes of integrating quality and security practices. This research would be of value to researchers as it introduces the security component of software quality into a solo software development environment, probing more research in the area. To software developers the research has provided a lightweight methodology that builds quality and security into the product using minimum resources. / School of Computing / D. Phil. (Computer Science)

Zero-days are vulnerabilities that the software vendor does not know about and thus cannot provide a patch for. Their value has caused markets to develop, divided by the purchase intention. This thesis focuses on the white and grey markets, that is those buying to patch and those buying to exploit. While states generally have an interest in both, they currently spend money to exploit zerodays, keeping software insecure. The lack of knowledge and awareness surrounding this practice is the problem targeted in this thesis. Serious games, aiming to be both entertaining and educational, represent one opportunity to create awareness. They fit our circumstances particularly well because understanding the problem space requires adversarial thinking and lots of different concepts. Our research goal has thus been to create a serious game that accurately illuminates the dilemma experienced by states. Design science was the research strategy employed to reach the stated goal. Our main contribution is Minimator, a multiplayer, web-based game in which players, acting as states, have to protect their infrastructure and deal with zero-day markets. Additionally, we present a formal model of states’ treatment of zero-day markets developed using game theory and shown to resemble the n-players prisoners’ dilemma. An expert evaluation was conducted, delivering promising results in terms of gameplay appeal, and accuracy. A naturalistic evaluation remains, but is suggested in detail for future endeavours. Minimator is original as, to our knowledge, no similar artefact exists. It provides value by potentially creating a starting point for and encouraging an informed, public debate about the trade-off between national and infrastructure security, which is inherently political.