1,720,975 research outputs found

    Recognizing self-mutating malware by code normalization and control-flow graph analysis

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    Next-generation malware will adopt self-mutation to circumvent current malware detection techniques. The authors propose a strategy based on code normalization that reduces different instances of the same malware into a common form that can enable accurate detection

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed

    FluXOR : detecting and monitoring fast-flux service networks

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    Botnets are large groups of compromised machines (bots) used by miscreants for the most illegal activities (e.g., sending spam emails, denial-of-service attacks, phishing and other web scams). To protect the identity and to maximise the availability of the core components of their business, miscreants have recently started to use fast-flux service networks, large groups of bots acting as front-end proxies to these components. Motivated by the conviction that prompt detection and monitoring of these networks is an essential step to contrast the problem posed by botnets, we have developed FluXOR, a system to detect and monitor fast-flux service networks. FluXOR monitoring and detection strategies entirely rely on the analysis of a set of features observable from the point of view of a victim of the scams perpetrated thorough botnets. We have been using FluXOR for about a month and so far we have detected 387 fast-flux service networks, totally composed by 31998 distinct compromised machines, which we believe to be associated with 16 botnets

    Testing CPU emulators

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    A CPU emulator is a software that simulates a hardware CPU. Emulators are widely used by computer scientists for various kind of activities (e.g., debugging, profiling, and malware analysis). Although no theoretical limitation prevents to develop an emulator that faithfully emulates a physical CPU, writing a fully featured emulator is a very challenging and error-prone task. Modern CISC architectures have a very rich instruction set, some instructions lack proper specifications, and others may have undefined effects in corner-cases. This paper presents a testing methodology specific for CPU emulators, based on fuzzing. The emulator is "stressed" with specially crafted test-cases, to verify whether the CPU is properly emulated or not. Improper behaviours of the emulator are detected by running the same test-case concurrently on the emulated and on the physical CPUs and by comparing the state of the two after the execution. Differences in the final state testify defects in the code of the emulator. We implemented this methodology in a prototype (codenamed EmuFuzzer), analysed four state-of-the-art IA-32 emulators (QEMU, Valgrind, Pin and BOCHS), and found several defects in each of them, some of which can prevent the proper execution of programs

    Variations on the Author

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    “Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship

    Appropriate Similarity Measures for Author Cocitation Analysis

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    We provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis

    How good are malware detectors at remediating infected systems?

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    Malware detectors are applications that attempt to identify and block malicious programs. Unfortunately, malware detectors might not always be able to preemptively block a malicious program from infecting the system (e.g., when the signatures database is not promptly updated). In these situations, the only way to eradicate the infection without having to reinstall the entire system is to rely on the remediation capabilities of the detectors. Therefore, it is essential to evaluate the efficacy and accuracy of anti-malware software in such situations. This paper presents a testing methodology to assess the quality (completeness) of the remediation procedures used by malware detectors to revert the effect of an infection from a compromised system. To evaluate the efficacy of our testing methodology, we developed a prototype and used it to test six of the top-rated commercial malware detectors currently available on the market. The results of our evaluation witness that in many situations the tested malware detectors fail to completely remove the effects of an infection

    Dispelling the Myths Behind First-author Citation Counts

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    We conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more sophisticated methods
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