26 research outputs found

    Hardware trojans against virtual keyboards on e-banking platforms - A proof of concept

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    In the last years there has been a considerable growth on the number of users id on-line banking (Szopinski, 2016). Banks must implement strong security solutions and users have to feel safe about the security offered. To securize the users' access, virtual keyboards are commonly used. Unlikely, virtual keyboards are vulnerable to shoulder surfing and malicious software-based attacks such as malware and Trojans (Nadkarni et al., 2011; Sapra et al., 2013). In this article we propose a Hardware Trojan (HT), which targets a VGA display and is able to reveal the private information clicked by the user on a virtual keyboard. This HT is very harmful since it defeats the countermeasures (e.g., keyboard mutation or obfuscation) generally used to combat malicious pieces of software (Nayak et al., 2014; Parekh et al., 2011; Rajarajan et al., 2014).This work was supported by the MINECO – Spain grant: TIN2013-46469-R (SPINY: Security and Privacy in the Internet of You) and the CAM – Comunidad Autónoma de Madrid grant S2013/ICE-3095 (CIBERDINE: Cybersecurity, Data, and Risks)

    Enhancing Web Browsing Security

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    Web browsing has become an integral part of our lives, and we use browsers to perform many important activities almost everyday and everywhere. However, due to the vulnerabilities in Web browsers and Web applications and also due to Web users\u27 lack of security knowledge, browser-based attacks are rampant over the Internet and have caused substantial damage to both Web users and service providers. Enhancing Web browsing security is therefore of great need and importance.;This dissertation concentrates on enhancing the Web browsing security through exploring and experimenting with new approaches and software systems. Specifically, we have systematically studied four challenging Web browsing security problems: HTTP cookie management, phishing, insecure JavaScript practices, and browsing on untrusted public computers. We have proposed new approaches to address these problems, and built unique systems to validate our approaches.;To manage HTTP cookies, we have proposed an approach to automatically validate the usefulness of HTTP cookies at the client-side on behalf of users. By automatically removing useless cookies, our approach helps a user to strike an appropriate balance between maximizing usability and minimizing security risks. to protect against phishing attacks, we have proposed an approach to transparently feed a relatively large number of bogus credentials into a suspected phishing site. Using those bogus credentials, our approach conceals victims\u27 real credentials and enables a legitimate website to identify stolen credentials in a timely manner. to identify insecure JavaScript practices, we have proposed an execution-based measurement approach and performed a large-scale measurement study. Our work sheds light on the insecure JavaScript practices and especially reveals the severity and nature of insecure JavaScript inclusion and dynamic generation practices on the Web. to achieve secure and convenient Web browsing on untrusted public computers, we have proposed a simple approach that enables an extended browser on a mobile device and a regular browser on a public computer to collaboratively support a Web session. A user can securely perform sensitive interactions on the mobile device and conveniently perform other browsing interactions on the public computer

    Towards understanding and mitigating attacks leveraging zero-day exploits

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    Zero-day vulnerabilities are unknown and therefore not addressed with the result that they can be exploited by attackers to gain unauthorised system access. In order to understand and mitigate against attacks leveraging zero-days or unknown techniques, it is necessary to study the vulnerabilities, exploits and attacks that make use of them. In recent years there have been a number of leaks publishing such attacks using various methods to exploit vulnerabilities. This research seeks to understand what types of vulnerabilities exist, why and how these are exploited, and how to defend against such attacks by either mitigating the vulnerabilities or the method / process of exploiting them. By moving beyond merely remedying the vulnerabilities to defences that are able to prevent or detect the actions taken by attackers, the security of the information system will be better positioned to deal with future unknown threats. An interesting finding is how attackers exploit moving beyond the observable bounds to circumvent security defences, for example, compromising syslog servers, or going down to lower system rings to gain access. However, defenders can counter this by employing defences that are external to the system preventing attackers from disabling them or removing collected evidence after gaining system access. Attackers are able to defeat air-gaps via the leakage of electromagnetic radiation as well as misdirect attribution by planting false artefacts for forensic analysis and attacking from third party information systems. They analyse the methods of other attackers to learn new techniques. An example of this is the Umbrage project whereby malware is analysed to decide whether it should be implemented as a proof of concept. Another important finding is that attackers respect defence mechanisms such as: remote syslog (e.g. firewall), core dump files, database auditing, and Tripwire (e.g. SlyHeretic). These defences all have the potential to result in the attacker being discovered. Attackers must either negate the defence mechanism or find unprotected targets. Defenders can use technologies such as encryption to defend against interception and man-in-the-middle attacks. They can also employ honeytokens and honeypots to alarm misdirect, slow down and learn from attackers. By employing various tactics defenders are able to increase their chance of detecting and time to react to attacks, even those exploiting hitherto unknown vulnerabilities. To summarize the information presented in this thesis and to show the practical importance thereof, an examination is presented of the NSA's network intrusion of the SWIFT organisation. It shows that the firewalls were exploited with remote code execution zerodays. This attack has a striking parallel in the approach used in the recent VPNFilter malware. If nothing else, the leaks provide information to other actors on how to attack and what to avoid. However, by studying state actors, we can gain insight into what other actors with fewer resources can do in the future

    Web-based Secure Application Control

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    The world wide web today serves as a distributed application platform. Its origins, however, go back to a simple delivery network for static hypertexts. The legacy from these days can still be observed in the communication protocol used by increasingly sophisticated clients and applications. This thesis identifies the actual security requirements of modern web applications and shows that HTTP does not fit them: user and application authentication, message integrity and confidentiality, control-flow integrity, and application-to-application authorization. We explore the other protocols in the web stack and work out why they can not fill the gap. Our analysis shows that the underlying problem is the connectionless property of HTTP. However, history shows that a fresh start with web communication is far from realistic. As a consequence, we come up with approaches that contribute to meet the identified requirements. We first present impersonation attack vectors that begin before the actual user authentication, i.e. when secure web interaction and authentication seem to be unnecessary. Session fixation attacks exploit a responsibility mismatch between the web developer and the used web application framework. We describe and compare three countermeasures on different implementation levels: on the source code level, on the framework level, and on the network level as a reverse proxy. Then, we explain how the authentication credentials that are transmitted for the user login, i.e. the password, and for session tracking, i.e. the session cookie, can be complemented by browser-stored and user-based secrets respectively. This way, an attacker can not hijack user accounts only by phishing the user's password because an additional browser-based secret is required for login. Also, the class of well-known session hijacking attacks is mitigated because a secret only known by the user must be provided in order to perform critical actions. In the next step, we explore alternative approaches to static authentication credentials. Our approach implements a trusted UI and a mutually authenticated session using signatures as a means to authenticate requests. This way, it establishes a trusted path between the user and the web application without exchanging reusable authentication credentials. As a downside, this approach requires support on the client side and on the server side in order to provide maximum protection. Another approach avoids client-side support but can not implement a trusted UI and is thus susceptible to phishing and clickjacking attacks. Our approaches described so far increase the security level of all web communication at all time. This is why we investigate adaptive security policies that fit the actual risk instead of permanently restricting all kinds of communication including non-critical requests. We develop a smart browser extension that detects when the user is authenticated on a website meaning that she can be impersonated because all requests carry her identity proof. Uncritical communication, however, is released from restrictions to enable all intended web features. Finally, we focus on attacks targeting a web application's control-flow integrity. We explain them thoroughly, check whether current web application frameworks provide means for protection, and implement two approaches to protect web applications: The first approach is an extension for a web application framework and provides protection based on its configuration by checking all requests for policy conformity. The second approach generates its own policies ad hoc based on the observed web traffic and assuming that regular users only click on links and buttons and fill forms but do not craft requests to protected resources.Das heutige World Wide Web ist eine verteilte Plattform für Anwendungen aller Art: von einfachen Webseiten über Online Banking, E-Mail, multimediale Unterhaltung bis hin zu intelligenten vernetzten Häusern und Städten. Seine Ursprünge liegen allerdings in einem einfachen Netzwerk zur Übermittlung statischer Inhalte auf der Basis von Hypertexten. Diese Ursprünge lassen sich noch immer im verwendeten Kommunikationsprotokoll HTTP identifizieren. In dieser Arbeit untersuchen wir die Sicherheitsanforderungen moderner Web-Anwendungen und zeigen, dass HTTP diese Anforderungen nicht erfüllen kann. Zu diesen Anforderungen gehören die Authentifikation von Benutzern und Anwendungen, die Integrität und Vertraulichkeit von Nachrichten, Kontrollflussintegrität und die gegenseitige Autorisierung von Anwendungen. Wir untersuchen die Web-Protokolle auf den unteren Netzwerk-Schichten und zeigen, dass auch sie nicht die Sicherheitsanforderungen erfüllen können. Unsere Analyse zeigt, dass das grundlegende Problem in der Verbindungslosigkeit von HTTP zu finden ist. Allerdings hat die Geschichte gezeigt, dass ein Neustart mit einem verbesserten Protokoll keine Option für ein gewachsenes System wie das World Wide Web ist. Aus diesem Grund beschäftigt sich diese Arbeit mit unseren Beiträgen zu sicherer Web-Kommunikation auf der Basis des existierenden verbindungslosen HTTP. Wir beginnen mit der Beschreibung von Session Fixation-Angriffen, die bereits vor der eigentlichen Anmeldung des Benutzers an der Web-Anwendung beginnen und im Erfolgsfall die temporäre Übernahme des Benutzerkontos erlauben. Wir präsentieren drei Gegenmaßnahmen, die je nach Eingriffsmöglichkeiten in die Web-Anwendung umgesetzt werden können. Als nächstes gehen wir auf das Problem ein, dass Zugangsdaten im WWW sowohl zwischen den Teilnehmern zu Authentifikationszwecken kommuniziert werden als auch für jeden, der Kenntnis dieser Daten erlangt, wiederverwendbar sind. Unsere Ansätze binden das Benutzerpasswort an ein im Browser gespeichertes Authentifikationsmerkmal und das sog. Session-Cookie an ein Geheimnis, das nur dem Benutzer und der Web-Anwendung bekannt ist. Auf diese Weise kann ein Angreifer weder ein gestohlenes Passwort noch ein Session-Cookie allein zum Zugriff auf das Benutzerkonto verwenden. Darauffolgend beschreiben wir ein Authentifikationsprotokoll, das vollständig auf die Übermittlung geheimer Zugangsdaten verzichtet. Unser Ansatz implementiert eine vertrauenswürdige Benutzeroberfläche und wirkt so gegen die Manipulation derselben in herkömmlichen Browsern. Während die bisherigen Ansätze die Sicherheit jeglicher Web-Kommunikation erhöhen, widmen wir uns der Frage, inwiefern ein intelligenter Browser den Benutzer - wenn nötig - vor Angriffen bewahren kann und - wenn möglich - eine ungehinderte Kommunikation ermöglichen kann. Damit trägt unser Ansatz zur Akzeptanz von Sicherheitslösungen bei, die ansonsten regelmäßig als lästige Einschränkungen empfunden werden. Schließlich legen wir den Fokus auf die Kontrollflussintegrität von Web-Anwendungen. Bösartige Benutzer können den Zustand von Anwendungen durch speziell präparierte Folgen von Anfragen in ihrem Sinne manipulieren. Unsere Ansätze filtern Benutzeranfragen, die von der Anwendung nicht erwartet wurden, und lassen nur solche Anfragen passieren, die von der Anwendung ordnungsgemäß verarbeitet werden können

    Data Exfiltration:A Review of External Attack Vectors and Countermeasures

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    AbstractContext One of the main targets of cyber-attacks is data exfiltration, which is the leakage of sensitive or private data to an unauthorized entity. Data exfiltration can be perpetrated by an outsider or an insider of an organization. Given the increasing number of data exfiltration incidents, a large number of data exfiltration countermeasures have been developed. These countermeasures aim to detect, prevent, or investigate exfiltration of sensitive or private data. With the growing interest in data exfiltration, it is important to review data exfiltration attack vectors and countermeasures to support future research in this field. Objective This paper is aimed at identifying and critically analysing data exfiltration attack vectors and countermeasures for reporting the status of the art and determining gaps for future research. Method We have followed a structured process for selecting 108 papers from seven publication databases. Thematic analysis method has been applied to analyse the extracted data from the reviewed papers. Results We have developed a classification of (1) data exfiltration attack vectors used by external attackers and (2) the countermeasures in the face of external attacks. We have mapped the countermeasures to attack vectors. Furthermore, we have explored the applicability of various countermeasures for different states of data (i.e., in use, in transit, or at rest). Conclusion This review has revealed that (a) most of the state of the art is focussed on preventive and detective countermeasures and significant research is required on developing investigative countermeasures that are equally important; (b) Several data exfiltration countermeasures are not able to respond in real-time, which specifies that research efforts need to be invested to enable them to respond in real-time (c) A number of data exfiltration countermeasures do not take privacy and ethical concerns into consideration, which may become an obstacle in their full adoption (d) Existing research is primarily focussed on protecting data in ‘in use’ state, therefore, future research needs to be directed towards securing data in ‘in rest’ and ‘in transit’ states (e) There is no standard or framework for evaluation of data exfiltration countermeasures. We assert the need for developing such an evaluation framework

    Authentication and Data Protection under Strong Adversarial Model

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    We are interested in addressing a series of existing and plausible threats to cybersecurity where the adversary possesses unconventional attack capabilities. Such unconventionality includes, in our exploration but not limited to, crowd-sourcing, physical/juridical coercion, substantial (but bounded) computational resources, malicious insiders, etc. Our studies show that unconventional adversaries can be counteracted with a special anchor of trust and/or a paradigm shift on a case-specific basis. Complementing cryptography, hardware security primitives are the last defense in the face of co-located (physical) and privileged (software) adversaries, hence serving as the special trust anchor. Examples of hardware primitives are architecture-shipped features (e.g., with CPU or chipsets), security chips or tokens, and certain features on peripheral/storage devices. We also propose changes of paradigm in conjunction with hardware primitives, such as containing attacks instead of counteracting, pretended compliance, and immunization instead of detection/prevention. In this thesis, we demonstrate how our philosophy is applied to cope with several exemplary scenarios of unconventional threats, and elaborate on the prototype systems we have implemented. Specifically, Gracewipe is designed for stealthy and verifiable secure deletion of on-disk user secrets under coercion; Hypnoguard protects in-RAM data when a computer is in sleep (ACPI S3) in case of various memory/guessing attacks; Uvauth mitigates large-scale human-assisted guessing attacks by receiving all login attempts in an indistinguishable manner, i.e., correct credentials in a legitimate session and incorrect ones in a plausible fake session; Inuksuk is proposed to protect user files against ransomware or other authorized tampering. It augments the hardware access control on self-encrypting drives with trusted execution to achieve data immunization. We have also extended the Gracewipe scenario to a network-based enterprise environment, aiming to address slightly different threats, e.g., malicious insiders. We believe the high-level methodology of these research topics can contribute to advancing the security research under strong adversarial assumptions, and the promotion of software-hardware orchestration in protecting execution integrity therein

    Virtual Reality Games for Motor Rehabilitation

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    This paper presents a fuzzy logic based method to track user satisfaction without the need for devices to monitor users physiological conditions. User satisfaction is the key to any product’s acceptance; computer applications and video games provide a unique opportunity to provide a tailored environment for each user to better suit their needs. We have implemented a non-adaptive fuzzy logic model of emotion, based on the emotional component of the Fuzzy Logic Adaptive Model of Emotion (FLAME) proposed by El-Nasr, to estimate player emotion in UnrealTournament 2004. In this paper we describe the implementation of this system and present the results of one of several play tests. Our research contradicts the current literature that suggests physiological measurements are needed. We show that it is possible to use a software only method to estimate user emotion
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