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Dissertations / Theses on the topic 'Computer viruses'
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Luke, James Steven. "Detecting previously unseen computer viruses." Thesis, University of Southampton, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.274015.
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Szeto, Wai-chi. "Computer virus prevention and control in Hong Kong /." [Hong Kong] : University of Hong Kong, 1993. http://sunzi.lib.hku.hk/hkuto/record.jsp?B13302371.
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Posluszny, Frank S. "Overcoming limitations in computer worm models." Link to electronic thesis, 2005. http://www.wpi.edu/Pubs/ETD/Available/etd-01315-115046.
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Weideman, Melius. "A critical evaluation of the destructive impact of computer viruses on files stored by personal computer users." Thesis, Cape Technikon, 1994. http://hdl.handle.net/20.500.11838/1363.
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Thesis (Masters Diploma (Information Technology))--Cape Technikon, Cape Town, 1994Computer virus programs are generally perceived to be a threat to the information stored by computer users. This research evaluated the impact computer viruses have on information stored by computer users. The emphasis was on the effects of computer viruses rather than on the detail of their operation. The main hypotheses involved the question of whether or not computer viruses do pose a threat to the information stored by computer users. The effect of computer viruses on the information of users in industry was measured by sending a questionnaire to 388 companies country-wide. &~ average of 2l,5% of the respondents claimed detrimental effects to information stored on disk due to computer viruses. This and other data was used to guide laboratory experiments on the actual damage done by computer viruses to stored information. A set of test disks was prepared to represent programs and data of a typical PC user in industry. Fifteen different virus programs were used individually to infect the test disks. After each infection, all the test disks were inspected to ascertain damage to data, system and program files as well as to separate disk sectors. The research established that: The damage done by computer viruses to stored information is generally limited to one file or disk area. Where damage to stored information did occur, it was often reversible. Irrational user responses to virus symptoms provide a large potential source for damage to stored information. The availability of master program disks (for program file restoration) and recent, validated data backup is essential to recovery from a computer virus infection. A user can solve most problems caused by virus infections if he has a basic understanding of disk structure, i.e. tracks, sectors, sides, the FAT, etc, and of the use of disk utility programs like Norton Utilities or PCTools. The fact that some of the findings of prominent virus researchers could not be verified, suggests that virus programs could be unstable. Claims regarding the damage inflicted by viruses must be considered to be valid only for a specific copy of the virus under discussion. The importance of using original application software (to minimize the transfer of viruses and to enable program file restoration) , regular back-ups (to enable data file restoration) and basic user awareness (infection prevention, symptoms, the use of anti-viral and utility programs, etc.) was emphasized. The average PC user should be able to clear up a virus infection without assistance by following the given disinfection procedure. Suggestions for further study include virus origins, generations, mutations, multiple infections, and the effect of viruses on computer networks.
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Schultz, John S. "Offline forensic analysis of Microsoft Windows XP physical memory." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2006. http://library.nps.navy.mil/uhtbin/hyperion/06Sep%5FSchultz.pdf.
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Thesis (M.S. in Computer Science)--Naval Postgraduate School, September 2006.Thesis Advisor(s): Chris Eagle. "September 2006." Includes bibliographical references (p. 73-74). Also available in print.
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Li, Xin. "Computer viruses: The threat today and the expected future." Thesis, Linköping University, Department of Electrical Engineering, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-1998.
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This Master’s Thesis within the area computer security concerns ”Computer viruses: The threat today and the expected future”.
Firstly, the definitions of computer virus and the related threats are presented; Secondly, current situation of computer viruses are discussed, the working and spreading mechanisms of computer viruses are reviewed in details, simplistic attitude of computer world in computer virus defence is analyzed; Thirdly, today’s influencing factors for near future computer virus epidemics are explained, then it further predicts new possible types of computer viruses in the near future; Furthermore, currently available anti-virus technologies are analyzed concerning both advantages and disadvantages; Finally, new promising trends in computer virus defence are explored in details.
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Posluszny, III Frank S. "Overcoming Limitations in Computer Worm Models." Digital WPI, 2005. https://digitalcommons.wpi.edu/etd-theses/151.
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In less than two decades, destruction and abuse caused by computer viruses and worms have grown from an anomaly to an everyday occurrence. In recent years, the Computer Emergency Response Team (CERT) has recorded a steady increase in software defects and vulnerabilities, similar to those exploited by the Slammer and Code Red worms. In response to such a threat, the academic community has started a set of research projects seeking to understand worm behavior through creation of highly theoretical and generalized models. Staniford et. al. created a model to explain the propagation behaviors of such worms in computer network environments. Their model makes use of the Kermack-McKendrick biological model of propagation as applied to digital systems. Liljenstam et. al. add a spatial perspective to this model, varying the infection rate by the scanning worms' source and destination groups. These models have been shown to describe generic Internet-scale behavior. However, they are lacking from a localized (campus-scale) network perspective. We make the claim that certain real-world constraints, such as bandwidth and heterogeneity of hosts, affect the propagation of worms and thus should not be ignored when creating models for analysis. In setting up a testing environment for this hypothesis, we have identified areas that need further work in the computer worm research community. These include availability of real-world data, a generalized and behaviorally complete worm model, and packet-based simulations. The major contributions of this thesis involve a parameterized, algorithmic worm model, an openly available worm simulation package (based on SSFNet and SSF.App.Worm), analysis of test results showing justification to our claim, and suggested future directions.
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Webster, Matthew Paul. "Formal models of reproduction : from computer viruses to artificial life." Thesis, University of Liverpool, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.501590.
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In this thesis we describe novel approaches to the formal description of systems which reproduce, and show that the resulting models have explanatory power and practical applications, particularly in the domain of computer virology. We start by generating a formal description of computer viruses based on formal methods and notations developed for software engineering. We then prove that our model can be used to detect metamorphic computer viruses, which are designed specifically to avoid well-established signature-based detection methods. Next, we move away from the specific case of reproducing programs, and consider formal models of reproducing things in general. We show that we can develop formal models of the ecology of a reproducer, based on a formalisation of Gibson's theory of affordances.
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林衛華 and Wai-wa Lam. "Multi-agent based human immune system." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1999. http://hub.hku.hk/bib/B31221117.
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Lam, Wai-wa. "Multi-agent based human immune system /." Hong Kong : University of Hong Kong, 1999. http://sunzi.lib.hku.hk/hkuto/record.jsp?B2093337X.
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Szeto, Wai-chi, and 司徒偉慈. "Computer virus prevention and control in Hong Kong." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1992. http://hub.hku.hk/bib/B31265479.
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Lin, Meng-jang. "The impact of population mixing rules on epidemic communication /." Digital version accessible at:, 1999. http://wwwlib.umi.com/cr/utexas/main.
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Saw, Tee Huu. "Evaluation of a multi-agent system for simulation and analysis of distributed denial-of-service attacks." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2003. http://library.nps.navy.mil/uhtbin/hyperion-image/03Dec%5FSaw.pdf.
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Thesis (M.S. in Computer Science)--Naval Postgraduate School, December 2003.Thesis advisor(s): James B. Michael, Mikhail Auguston. Includes bibliographical references (p. 52-54). Also available online.
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Pande, Rishikesh A. "Using Plant Epidemiological Methods to Track Computer Network Worms." Thesis, Virginia Tech, 2004. http://hdl.handle.net/10919/9943.
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Network worms that scan random computers have caused billions of dollars in damage to enterprises across the Internet. Earlier research has concentrated on using epidemiological models to predict the number of computers a worm will infect and how long it takes to do so. In this research, one possible approach is outlined for predicting the spatial flow of a worm within the local area network (LAN).
The approach in this research is based on the application of mathematical models and variables inherent in plant epidemiology. In particular, spatial autocorrelation has been identified as a candidate variable that helps predict the spread of a worm over a LAN. This research describes the application of spatial autocorrelation to the geography and topology of the LAN and describes the methods used to determine spatial autocorrelation. Also discussed is the data collection process and methods used to extract pertinent information. Data collection and analyses are applied to the spread of three historical network worms on the Virginia Tech campus and the results are described.
Spatial autocorrelation exists in the spread of network worms across the Virginia Tech campus when the geographic aspect is considered. If a new network worm were to start spreading across Virginia Tech's campus, spatial autocorrelation would facilitate tracking the geographical locations of the spread. In addition if an infection with a known value of spatial autocorrelation is detected, the characteristics of the worm can be identified without a complete analysis.Master of Science
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Yelimeli, Guruprasad Arun. "Computer Virus Spread Containment Using Feedback Control." Thesis, University of North Texas, 2004. https://digital.library.unt.edu/ark:/67531/metadc4675/.
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In this research, a security architecture based on the feedback control theory has been proposed. The first loop has been designed, developed and tested. The architecture proposes a feedback model with many controllers located at different stages of network. The controller at each stage gives feedback to the one at higher level and a decision about network security is taken. The first loop implemented in this thesis detects one important anomaly of virus attack, rate of outgoing connection. Though there are other anomalies of a virus attack, rate of outgoing connection is an important one to contain the spread. Based on the feedback model, this symptom is fed back and a state model using queuing theory is developed to delay the connections and slow down the rate of outgoing connections. Upon implementation of this model, whenever an infected machine tries to make connections at a speed not considered safe, the controller kicks in and sends those connections to a delay queue. Because of delaying connections, rate of outgoing connections decrease. Also because of delaying, many connections timeout and get dropped, reducing the spread. PID controller is implemented to decide the number of connections going to safe or suspected queue. Multiple controllers can be implemented to control the parameters like delay and timeout. Control theory analysis is performed on the system to test for stability, controllability, observability. Sensitivity analysis is done to find out the sensitivity of the controller to the delay parameter. The first loop implemented gives feedback to the architecture proposed about symptoms of an attack at the node level. A controller needs to be developed to receive information from different controllers and decision about quarantining needs to be made. This research gives the basic information needed for the controller about what is going on at individual nodes of the network. This information can also be used to increase sensitivity of other loops to increase the effectiveness of feedback architecture.
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Twardus, Jesse. "The use of heuristics in identifying self-propagating malicious mobile code." Morgantown, W. Va. : [West Virginia University Libraries], 2005. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=4195.
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Thesis (M.S.)--West Virginia University, 2005.Title from document title page. Document formatted into pages; contains viii, 104 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 89-92).
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Dai, Jianyong. "Detecting malicious software by dynamic execution." Orlando, Fla. : University of Central Florida, 2009. http://purl.fcla.edu/fcla/etd/CFE0002798.
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White, Dominic Stjohn Dolin. "Limiting vulnerability exposure through effective patch management: threat mitigation through vulnerability remediation." Thesis, Rhodes University, 2007. http://hdl.handle.net/10962/d1006510.
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This document aims to provide a complete discussion on vulnerability and patch management. The first chapters look at the trends relating to vulnerabilities, exploits, attacks and patches. These trends describe the drivers of patch and vulnerability management and situate the discussion in the current security climate. The following chapters then aim to present both policy and technical solutions to the problem. The policies described lay out a comprehensive set of steps that can be followed by any organisation to implement their own patch management policy, including practical advice on integration with other policies, managing risk, identifying vulnerability, strategies for reducing downtime and generating metrics to measure progress. Having covered the steps that can be taken by users, a strategy describing how best a vendor should implement a related patch release policy is provided. An argument is made that current monthly patch release schedules are inadequate to allow users to most effectively and timeously mitigate vulnerabilities. The final chapters discuss the technical aspect of automating parts of the policies described. In particular the concept of 'defense in depth' is used to discuss additional strategies for 'buying time' during the patch process. The document then goes on to conclude that in the face of increasing malicious activity and more complex patching, solid frameworks such as those provided in this document are required to ensure an organisation can fully manage the patching process. However, more research is required to fully understand vulnerabilities and exploits. In particular more attention must be paid to threats, as little work as been done to fully understand threat-agent capabilities and activities from a day to day basis.TeX output 2007.02.08:2212
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Khayam, Syed Ali. "Wireless channel modeling and malware detection using statistical and information-theoretic tools." Diss., Connect to online resource - MSU authorized users, 2006.
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Thesis (Ph. D.)--Michigan State University. Dept. of Electrical and Computer Engineering, 2006.Title from PDF t.p. (viewed on June 19, 2009) Includes bibliographic references. Also issued in print.
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Volynkin, Alexander S. "Advanced methods for detection of malicious software." Diss., Online access via UMI:, 2007.
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Lobo, Desmond. "Rapid identification of rootkit infections using data mining." Thesis, University of Ballarat, 2010. http://researchonline.federation.edu.au/vital/access/HandleResolver/1959.17/44308.
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"The main part of this thesis presents a new approach to the topic of conjugation, with applications to various optimization problems. It does so by introducing (what we call) G-coupling functions."Doctor of Philsophy
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Al, Amro Sulaiman. "Behaviour-based virus analysis and detection." Thesis, De Montfort University, 2013. http://hdl.handle.net/2086/9488.
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Every day, the growing number of viruses causes major damage to computer systems, which many antivirus products have been developed to protect. Regrettably, existing antivirus products do not provide a full solution to the problems associated with viruses. One of the main reasons for this is that these products typically use signature-based detection, so that the rapid growth in the number of viruses means that many signatures have to be added to their signature databases each day. These signatures then have to be stored in the computer system, where they consume increasing memory space. Moreover, the large database will also affect the speed of searching for signatures, and, hence, affect the performance of the system. As the number of viruses continues to grow, ever more space will be needed in the future. There is thus an urgent need for a novel and robust detection technique. One of the most encouraging recent developments in virus research is the use of formulae, which provides alternatives to classic virus detection methods. The proposed research uses temporal logic and behaviour-based detection to detect viruses. Interval Temporal Logic (ITL) will be used to generate virus specifications, properties and formulae based on the analysis of the behaviour of computer viruses, in order to detect them. Tempura, which is the executable subset of ITL, will be used to check whether a good or bad behaviour occurs with the help of ITL description and system traces. The process will also use AnaTempura, an integrated workbench tool for ITL that supports our system specifications. AnaTempura will offer validation and verification of the ITL specifications and provide runtime testing of these specifications.
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Schoeman, Adam. "Amber : a aero-interaction honeypot with distributed intelligence." Thesis, Rhodes University, 2015. http://hdl.handle.net/10962/d1017938.
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For the greater part, security controls are based on the principle of Decision through Detection (DtD). The exception to this is a honeypot, which analyses interactions between a third party and itself, while occupying a piece of unused information space. As honeypots are not located on productive information resources, any interaction with it can be assumed to be non-productive. This allows the honeypot to make decisions based simply on the presence of data, rather than on the behaviour of the data. But due to limited resources in human capital, honeypots’ uptake in the South African market has been underwhelming. Amber attempts to change this by offering a zero-interaction security system, which will use the honeypot approach of decision through Presence (DtP) to generate a blacklist of third parties, which can be passed on to a network enforcer. Empirical testing has proved the usefulness of this alternative and low cost approach in defending networks. The functionality of the system was also extended by installing nodes in different geographical locations, and streaming their detections into the central Amber hive.
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Irwin, Barry Vivian William. "A framework for the application of network telescope sensors in a global IP network." Thesis, Rhodes University, 2011. http://hdl.handle.net/10962/d1004835.
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The use of Network Telescope systems has become increasingly popular amongst security researchers in recent years. This study provides a framework for the utilisation of this data. The research is based on a primary dataset of 40 million events spanning 50 months collected using a small (/24) passive network telescope located in African IP space. This research presents a number of differing ways in which the data can be analysed ranging from low level protocol based analysis to higher level analysis at the geopolitical and network topology level. Anomalous traffic and illustrative anecdotes are explored in detail and highlighted. A discussion relating to bogon traffic observed is also presented. Two novel visualisation tools are presented, which were developed to aid in the analysis of large network telescope datasets. The first is a three-dimensional visualisation tool which allows for live, near-realtime analysis, and the second is a two-dimensional fractal based plotting scheme which allows for plots of the entire IPv4 address space to be produced, and manipulated. Using the techniques and tools developed for the analysis of this dataset, a detailed analysis of traffic recorded as destined for port 445/tcp is presented. This includes the evaluation of traffic surrounding the outbreak of the Conficker worm in November 2008. A number of metrics relating to the description and quantification of network telescope configuration and the resultant traffic captures are described, the use of which it is hoped will facilitate greater and easier collaboration among researchers utilising this network security technology. The research concludes with suggestions relating to other applications of the data and intelligence that can be extracted from network telescopes, and their use as part of an organisation’s integrated network security systems
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Boardman, Anelda Philine. "Assessment of genome visualization tools relevant to HIV genome research: development of a genome browser prototype." Thesis, University of the Western Cape, 2004. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_3632_1185446929.
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Over the past two decades of HIV research, effective vaccine candidates have been elusive. Traditionally viral research has been characterized by a gene -by-gene approach, but in the light of the availability of complete genome sequences and the tractable size of the HIV genome, a genomic approach may improve insight into the biology and epidemiology of this virus. A genomic approach to finding HIV vaccine candidates can be facilitated by the use of genome sequence visualization. Genome browsers have been used extensively by various groups to shed light on the biology and evolution of several organisms including human, mouse, rat, Drosophila and C.elegans. Application of a genome browser to HIV genomes and related annotations can yield insight into forces that drive evolution, identify highly conserved regions as well as regions that yields a strong immune response in patients, and track mutations that appear over the course of infection. Access to graphical representations of such information is bound to support the search for effective HIV vaccine candidates. This study aimed to answer the question of whether a tool or application exists that can be modified to be used as a platform for development of an HIV visualization application and to assess the viability of such an implementation. Existing applications can only be assessed for their suitability as a basis for development of an HIV genome browser once a well-defined set of assessment criteria has been compiled.
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Atkison, Travis Levestis. "Using random projections for dimensionality reduction in identifying rogue applications." Diss., Mississippi State : Mississippi State University, 2009. http://library.msstate.edu/etd/show.asp?etd=etd-04032009-133701.
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Procházka, Ivo. "Analýza ransomwaru GlobeImposter." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2019. http://www.nusl.cz/ntk/nusl-400883.
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The aim of this diploma thesis is to analyze an instance of the GlobeImposter ransomware extracted from an affected device. The first part outlines various types of malware and ransomware and includes a description of encryption mechanisms and key distribution systems. It also discusses possible approaches of static and dynamic analysis of malware samples and requirements for test environments. The practical part describes the source of the malware sample, the physical and virtual test environment and the results of the static and dynamic analysis of the GlobeImposter ransomware. The final part discusses the results and the possibility of implementing a decryptor for the analyzed GlobeImposter ransomware.
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Sharif, Monirul Islam. "Robust and efficient malware analysis and host-based monitoring." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/37220.
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Today, host-based malware detection approaches such as antivirus programs are severely lagging in terms of defense against malware. Two important aspects that the overall effectiveness of malware detection depend on are the success of extracting information from malware using malware analysis to generate signatures, and then the success of utilizing these signatures on target hosts with appropriate system monitoring techniques. Today's malware employ a vast array of anti-analysis and anti-monitoring techniques to deter analysis and to neutralize antivirus programs, reducing the overall success of malware detection. In this dissertation, we present a set of practical approaches of robust and efficient malware analysis and system monitoring that can help make malware detection on hosts become more effective. First, we present a framework called Eureka, which efficiently deobfuscates single-pass and multi-pass packed binaries and restores obfuscated API calls, providing a basis for extracting comprehensive information from the malware using further static analysis. Second, we present the formal framework of transparent malware analysis and Ether, a dynamic malware analysis environment based on this framework that provides transparent fine-(single instruction) and coarse-(system call) granularity tracing. Third, we introduce an input-based obfuscation technique that hides trigger-based behavior from any input-oblivious analyzer. Fourth, we present an approach that automatically reverse-engineers the emulator and extracts the syntax and semantics of the bytecode language, which helps constructing control-flow graphs of the bytecode program and enables further analysis on the malicious code. Finally, we present Secure In-VM Monitoring, an approach of efficiently monitoring a target host while being robust against unknown malware that may attempt to neutralize security tools.
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Libuschewski, Pascal [Verfasser], Peter [Akademischer Betreuer] Marwedel, and Heinrich [Gutachter] Müller. "Exploration of cyber-physical systems for GPGPU computer vision-based detection of biological viruses / Pascal Libuschewski ; Gutachter: Heinrich Müller ; Betreuer: Peter Marwedel." Dortmund : Universitätsbibliothek Dortmund, 2017. http://d-nb.info/1129956806/34.
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Libuschewski, Pascal [Verfasser], Peter Akademischer Betreuer] Marwedel, and Heinrich [Gutachter] [Müller. "Exploration of cyber-physical systems for GPGPU computer vision-based detection of biological viruses / Pascal Libuschewski ; Gutachter: Heinrich Müller ; Betreuer: Peter Marwedel." Dortmund : Universitätsbibliothek Dortmund, 2017. http://nbn-resolving.de/urn:nbn:de:101:1-20170414167.
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Blaauw, Pieter. "Search engine poisoning and its prevalence in modern search engines." Thesis, Rhodes University, 2013. http://hdl.handle.net/10962/d1002037.
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The prevalence of Search Engine Poisoning in trending topics and popular search terms on the web within search engines is investigated. Search Engine Poisoning is the act of manipulating search engines in order to display search results from websites infected with malware. Research done between February and August 2012, using both manual and automated techniques, shows us how easily the criminal element manages to insert malicious content into web pages related to popular search terms within search engines. In order to provide the reader with a clear overview and understanding of the motives and the methods of the operators of Search Engine Poisoning campaigns, an in-depth review of automated and semi-automated web exploit kits is done, as well as looking into the motives for running these campaigns. Three high profile case studies are examined, and the various Search Engine Poisoning campaigns associated with these case studies are discussed in detail to the reader. From February to August 2012, data was collected from the top trending topics on Google’s search engine along with the top listed sites related to these topics, and then passed through various automated tools to discover if these results have been infiltrated by the operators of Search Engine Poisoning campaings, and the results of these automated scans are then discussed in detail. During the research period, manual searching for Search Engine Poisoning campaigns was also done, using high profile news events and popular search terms. These results are analysed in detail to determine the methods of attack, the purpose of the attack and the parties behind it
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Cowie, Bradley. "An exploratory study of techniques in passive network telescope data analysis." Thesis, Rhodes University, 2013. http://hdl.handle.net/10962/d1002038.
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Careful examination of the composition and concentration of malicious traffic in transit on the channels of the Internet provides network administrators with a means of understanding and predicting damaging attacks directed towards their networks. This allows for action to be taken to mitigate the effect that these attacks have on the performance of their networks and the Internet as a whole by readying network defences and providing early warning to Internet users. One approach to malicious traffic monitoring that has garnered some success in recent times, as exhibited by the study of fast spreading Internet worms, involves analysing data obtained from network telescopes. While some research has considered using measures derived from network telescope datasets to study large scale network incidents such as Code-Red, SQLSlammer and Conficker, there is very little documented discussion on the merits and weaknesses of approaches to analyzing network telescope data. This thesis is an introductory study in network telescope analysis and aims to consider the variables associated with the data received by network telescopes and how these variables may be analysed. The core research of this thesis considers both novel and previously explored analysis techniques from the fields of security metrics, baseline analysis, statistical analysis and technical analysis as applied to analysing network telescope datasets. These techniques were evaluated as approaches to recognize unusual behaviour by observing the ability of these techniques to identify notable incidents in network telescope datasets
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Rebiha, Rachid 1977. "Métodos formais algébricos para geração de invariantes." [s.n.], 2011. http://repositorio.unicamp.br/jspui/handle/REPOSIP/275741.
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Orientador: Arnaldo Vieira MouraTese (doutorado) - Universidade Estadual de Campinas, Instituto de Computação
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Resumo: É bem sabido que a automação e a eficácia de métodos de verificação formal de softwares, sistemas embarcados ou sistemas híbridos, depende da facilidade com que invariantes precisas possam ser geradas automaticamente a partir do código fonte. Uma invariante é uma propriedade, especificada sobre um local específico do código fonte, e que sempre se verifica a cada execução de um sistema. Apesar dos progressos enormes ao longo dos anos, o problema da geração de invariantes ainda está em aberto para tanto programas não-lineares discretos, como para sistemas não-lineares híbridos. Nesta tese, primeiramente, apresentamos novos métodos computacionais que podem automatizar a descoberta e o fortalecimento de relações não-lineares entre as variáveis de um programa que contém laços não-lineares, ou seja, programas que exibem relações polinomiais multivariadas e manipulações fracionarias. Além disso, a maioria dos sistemas de segurança críticos, tais como aviões, automóveis, produtos químicos, usinas de energia e sistemas biológicos, operam semanticamente como sistemas híbridos não-lineares. Nesse trabalho, apresentamos poderosos métodos computacionais que são capazes de gerar bases de ideais polinomiais de invariantes não-lineares para sistemas híbridos não-lineares. Em segundo lugar, apresentamos métodos pioneiros de verificação que automaticamente gerem bases de invariantes expressas por séries de potências multi-variáveis e por funções transcendentais. Discutimos, também, a sua convergência em sistemas híbridos que exibem modelos não lineares. Verificamos que as séries de potência geradas para invariantes são, muitas vezes, compostas pela expansão de algumas funções transcendentais bem conhecidas, tais como "log" e "exp". Assim, apresentam uma forma analisável fechada que facilita o uso de invariantes na verificação de propriedades de segurança. Para cada problema de geração de invariantes estabelecemos condições suficientes, muito gerais, que garantem a existência e permitem o cálculo dos ideais polinomiais para situações que não podem ser tratadas pelas abordagens de geração invariantes hoje conhecidas. Finalmente, estendemos o domínio de aplicações, acessíveis através de métodos de geração de invariantes, para a área de segurança. Mais precisamente, fornecemos uma plataforma extensível baseada em invariantes pré-computadas que seriam usadas como assinaturas semânticas para análise de intrusos ("malwares") e deteção dos ataques de intrusões mais virulentos. Seguindo a concepção de tais plataformas, propomos sistemas de detecção de intrusão, usando modelos gerados automaticamente, onde as chamadas de sistema e de funções são vigiados pela avaliação de invariantes, pré-calculadas para denunciar qualquer desvio observado durante a execução da aplicação. De modo abrangente, nesta tese, propomos a redução de problemas de geração de invariantes para problemas algébricos lineares. Ao reduzir os problemas de geração de invariante não-triviais de sistemas híbridos não-lineares para problemas algébricos lineares relacionados, somos capazes de ultrapassar as deficiências dos mais modernos métodos de geração de invariante hoje conhecidos permitindo, assim, a geração automática e eficiente de invariantes para programas e sistemas híbridos não lineares complexos. Tais métodos algébricos lineares apresentam complexidades computacionais significativamente inferiores àquelas exigidas pelos os fundamentos matemáticos das abordagens usadas hoje, tais como a computação de bases de Gröbner, a eliminação de quantificadores e decomposições cilíndricas algébricas
Abstract: It is well-known that the automation and effectiveness of formal software verification of embedded or hybrid systems depends to the ease with which precise invariants can be automatically generated from source specifications. An invariant is a property that holds true at a specific location in the specification code, whenever an execution reaches that location. Despite tremendous progress over the years, the problem of invariant generation remains very challenging for both non-linear discrete programs, as well as for non-linear hybrid systems. In this thesis, we first present new computational methods that can automate the discovery and can strengthen interrelationships among the variables of a program that contains non-linear loops, that is, programs that display multivariate polynomial and fractional manipulations. Moreover, most of safety-critical systems such as aircraft, cars, chemicals, power plants and biological systems operate semantically as non-linear hybrid systems. In this work, we demonstrate powerful computational methods that can generate basis for non-linear invariant ideals of non-linear hybrid systems. Secondly, we present the first verification methods that automatically generate basis for invariants expressed by multivariate formal power series and transcendental functions. We also discuss their convergence over hybrid systems that exhibit non linear models. The formal power series invariants generated are often composed by the expansion of some well-known transcendental functions e.g. log and exp. They also have an analysable closed-form which facilitates the use of the invariants when verifying safety properties. For each invariant generation problem, we establish very general sufficient conditions that guarantee the existence and allow for the computation of invariant ideals for situations that can not be treated in the presently known invariant generation approaches. Finally, we extend the domain of applications for invariant generation methods to encompass security problems. More precisely, we provide an extensible invariant-based platform for malware analysis and show how we can detect the most virulent intrusions attacks using these invariants. We propose to automatically generate invariants directly from the specified malware code in order to use them as semantic aware signatures, i.e. malware invariant, that would remain unchanged by most obfuscated techniques. Folix lowing the design of such platforms, we propose host-based intrusion detection systems, using automatically generated models where system calls are guarded by pre-computed invariants in order to report any deviation observed during the execution of the application. In a broad sense, in this thesis, we propose to reduce the verification problem of invariant generation to algebraic problems. By reducing the problems of non-trivial nonlinear invariant generation for programs and hybrid systems to related linear algebraic problems we are able to address various deficiencies of other state-of-the-art invariant generation methods, including the efficient treatment of complicated non-linear loop programs and non-linear hybrid systems. Such linear algebraic methods have much lower computational complexities than the mathematical foundations of previous approaches know today, which use techniques such as as Gröbner basis computation, quantifier elimination and cylindrical algebraic decomposition
Doutorado
Ciência da Computação
Doutor em Ciência da Computação
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Al-Salloum, Ziyad. "Topology-aware vulnerability mitigation worms." Thesis, Royal Holloway, University of London, 2011. http://repository.royalholloway.ac.uk/items/eec735f4-4649-4b31-285f-604bdaa4799c/10/.
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In very dynamic Information and Communication Technology (ICT) infrastructures, with rapidly growing applications, malicious intrusions have become very sophisticated, effective, and fast. Industries have suffered billions of US dollars losses due only to malicious worm outbreaks. Several calls have been issued by governments and industries to the research community to propose innovative solutions that would help prevent malicious breaches, especially with enterprise networks becoming more complex, large, and volatile. In this thesis we approach self-replicating, self-propagating, and self-contained network programs (i.e. worms) as vulnerability mitigation mechanisms to eliminate threats to networks. These programs provide distinctive features, including: Short distance communication with network nodes, intermittent network node vulnerability probing, and network topology discovery. Such features become necessary, especially for networks with frequent node association and disassociation, dynamically connected links, and where hosts concurrently run multiple operating systems. We propose -- to the best of our knowledge -- the first computer worm that utilize the second layer of the OSI model (Data Link Layer) as its main propagation medium. We name our defensive worm Seawave, a controlled interactive, self-replicating, self-propagating, and self-contained vulnerability mitigation mechanism. We develop, experiment, and evaluate Seawave under different simulation environments that mimic to a large extent enterprise networks. We also propose a threat analysis model to help identify weaknesses, strengths, and threats within and towards our vulnerability mitigation mechanism, followed by a mathematical propagation model to observe Seawave's performance under large scale enterprise networks. We also preliminary propose another vulnerability mitigation worm that utilizes the Link Layer Discovery Protocol (LLDP) for its propagation, along with an evaluation of its performance. In addition, we describe a preliminary taxonomy that rediscovers the relationship between different types of self-replicating programs (i.e. viruses, worms, and botnets) and redefines these programs based on their properties. The taxonomy provides a classification that can be easily applied within the industry and the research community and paves the way for a promising research direction that would consider the defensive side of self-replicating programs.
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Srivastava, Abhinav. "Robust and secure monitoring and attribution of malicious behaviors." Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/41161.
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Worldwide computer systems continue to execute malicious software that degrades the systemsâ performance and consumes network capacity by generating high volumes of unwanted traffic. Network-based detectors can effectively identify machines participating in the ongoing attacks by monitoring the traffic to and from the systems. But, network detection alone is not enough; it does not improve the operation of the Internet or the health of other machines connected to the network. We must identify malicious code running on infected systems, participating in global attack networks.
This dissertation describes a robust and secure approach that identifies malware present on infected systems based on its undesirable use of network. Our approach, using virtualization, attributes malicious traffic to host-level processes responsible for the traffic. The attribution identifies on-host processes, but malware instances often exhibit parasitic behaviors to subvert the execution of benign processes.
We then augment the attribution software with a host-level monitor that detects parasitic behaviors occurring at the user- and kernel-level. User-level parasitic attack detection happens via the system-call interface because it is a non-bypassable interface for user-level processes. Due to the unavailability of one such interface inside the kernel for drivers, we create a new driver monitoring interface inside the kernel to detect parasitic attacks occurring through this interface.
Our attribution software relies on a guest kernelâ s data to identify on-host processes. To allow secure attribution, we prevent illegal modifications of critical kernel data from kernel-level malware. Together, our contributions produce a unified research outcome --an improved malicious code identification system for user- and kernel-level malware.
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Mathuriya, Amrita. "Prediction of secondary structures for large RNA molecules." Thesis, Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/28195.
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Thesis (M. S.)--Computing, Georgia Institute of Technology, 2009.Committee Chair: Bader, David; Committee Co-Chair: Heitsch, Christine; Committee Member: Harvey, Stephen; Committee Member: Vuduc, Richard.
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Abdelhafez, Mohamed. "Modeling and Simulations of Worms and Mitigation Techniques." Diss., Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/19840.
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Internet worm attacks have become increasingly more frequent and have had a major impact on the economy, making the detection and prevention of these attacks a top security concern. Several countermeasures have been proposed and evaluated in recent literature. However, the eect of these proposed defensive mechanisms on legitimate competing traffic has not been analyzed.
The first contribution of this thesis is a comparative analysis of the effectiveness of
several of these proposed mechanisms, including a measure of their effect on normal web browsing activities. In addition, we introduce a new defensive approach that can easily be implemented on existing hosts, and which significantly reduces the rate of spread of worms
using TCP connections to perform the infiltration. Our approach has no measurable effect on legitimate traffic.
The second contribution is presenting a variant of the flash worm that we term Compact Flash or CFlash that is capable of spreading even faster than its predecessor. We perform a comparative study between the flash worm and the CFlash worm using a full-detail packet-level simulator, and the results show the increase in propagation rate of the new worm given the same set of parameters.
The third contribution is the study of the behavior of TCP based worms in MANETs. We develop an analytical model for the worm spread of TCP worms in the MANETs environment that accounts for payloadsize, bandwidthsharing, radio range, nodal density and several other parameters specific for MANET topologies. We also present numerical solutions for the model and verify the results using packetlevel simulations. The results show that the analytical model developed here matches the results of the packetlevel simulation in most cases.
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Castro, Diogo [UNIFESP]. "Simulação computacional e análise de um modelo fenotípico de evolução viral." Universidade Federal de São Paulo (UNIFESP), 2011. http://repositorio.unifesp.br/handle/11600/10085.
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Previous issue date: 2011-01-26Uma grande quantidade dos vírus de importância médica, como o HIV, o vírus sincicial respiratório, o vírus da hepatite C, o vírus influenza A (H1N1), e o vírus da poliomielite, possui genoma RNA. Estes vírus apresentam taxas mutacionais extremamente altas, rápida cinética replicativa, população numerosa de partículas, e grande diversidade genética. Manifestas durante o processo infeccioso, tais características permitem a população viral adaptar-se rapidamente a ambientes dinâmicos, escapar ao sistema imunológico, desenvolver resistência às vacinas e drogas antivirais, e exibir dinâmica evolutiva complexa cuja compreensão representa um desafio para a genética de populações tradicional e para as estratégias de intervenção terapêutica efetiva. Para descrever biológica e matematicamente a evolução dos vírus RNA, modelos teóricos de evolução viral têm sido propostos, e muitas de suas predições foram confirmadas experimentalmente. O presente trabalho teve como objetivo simular computacionalmente e analisar um modelo de evolução viral que represente relações evolutivas existentes entre a população viral de genoma RNA e as diferentes pressões seletivas exercidas sobre ela na sua interação com o organismo hospedeiro. Também objetivou desenvolver um software de simulação computacional personalizado para o modelo de evolução viral, e demonstrar a possibilidade de descrever o modelo como um processo de ramificação de Galton-Watson. Entre os resultados e discussões delineados, encontram-se um critério analítico para estudo do tempo de recuperação e do regime crítico de um processo de ramificação de Galton-Watson aplicado à evolução viral; predições sobre a correlação entre fatores do organismo hospedeiro e a dinâmica evolutiva da população viral; predições sobre a contribuição da taxa mutacional, do tamanho e da capacidade replicativa máxima da população viral para o prognóstico e quatro fases da infecção: o tempo de recuperação, o equilíbrio mutação-seleção, o limiar da extinção, e a mutagênese letal.
A large amount of viruses of medical importance such as HIV, respiratory syncytial virus, the hepatitis C virus, influenza A (H1N1) and polio virus, has RNA genome. These viruses exhibit extremely high mutational rate, fast replicative kinetics, large population of particles and high genetic diversity. Manifested during the infectious process, these features allow the virus population to adapt quickly to dynamic environments, escape from the immune system, develop resistance to vaccines and antiviral drugs, and display complex evolutionary dynamics whose understanding represents a challenge to the traditional population genetics and for effective therapeutic intervention strategies. To describe mathematically and biological evolution of RNA viruses, theoretical models of virus evolution have been proposed, and many of their predictions were experimentally confirmed. This study aimed to simulate and analyze computationally a model of viral evolution that represents evolutionary relationships between the population of viral RNA genome and the different selective pressures on it in its interaction with the host organism. It also aimed to develop computational simulation software for the viral evolution model, and demonstrate the possibility of describing the model as a Galton-Watson branching process. Among the results and discussions outlined, there are an analytical criterion to study the recovery time and the critical regime of a Galton-Watson branching process applied to viral evolution; predictions about the correlation between factors of the host organism and the evolutionary dynamics of viral population; predictions about the contribution of mutational rate, the size and maximum replicative capacity of viral population for the prognosis and four stages of infection: recovery time, mutation-selection equilibrium, extinction threshold, and lethal mutagenesis.
TEDE
BV UNIFESP: Teses e dissertações
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Arding, Petter, and Hugo Hedelin. "Computer virus : design and detection." Thesis, Linköpings universitet, Institutionen för datavetenskap, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-108484.
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Computer viruses uses a few different techniques, with various intentions, toinfect files. However, what most of them have in common is that they wantto avoid detection by anti-malware software. To not get detected and stay unnoticed,virus creators have developed several methods for this. Anti-malwaresoftware is constantly trying to counter these methods of virus infections withtheir own detection-techniques. In this paper we have analyzed the differenttypes of viruses and their infection techniques, and tried to determined whichworks the best to avoid detection. In the experiments we have done we havesimulated executing the viruses at the same time as an anti-malware softwarewas running. Our conclusion is that metamorphic viruses uses the best methodsto stay unnoticed by anti-malware software’s detection techniques.
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Sun, Jian. "Computer-aided drug design for influenza A virus." Click to view the E-thesis via HKUTO, 2009. http://sunzi.lib.hku.hk/hkuto/record/B44205156.
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Sun, Jian, and 孙健. "Computer-aided drug design for influenza A virus." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2009. http://hub.hku.hk/bib/B44205156.
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Salters, Michael Jerome. "Computer virus security in the Department of the Navy." Thesis, Monterey, California. Naval Postgraduate School, 1992. http://hdl.handle.net/10945/23842.
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Henchiri, Olivier. "A feature selection and evaluation scheme for computer virus detection." Thesis, University of Ottawa (Canada), 2006. http://hdl.handle.net/10393/27250.
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Computer viruses have existed since the early days of personal computers, and have since become a ubiquitous problem in the world of computing. The rate at which new viruses are created today and the age of networking have contributed to making anti-virus software a crucial aspect of just about every computer system. But while current virus detection methods provide good protection against known viruses, they remain primarily reactive to outbreaks, always one step behind the latest virus.
In our work, we implement a virus detection scheme that addresses this issue and focuses on improving the predictive power of a virus classifier on new viruses. We propose a hierarchical process for feature extraction that allows for an exhaustive feature search and, in contrast with current signature detection methods, obviates over-fitting.
We also introduce an evaluation scheme that relies on sub-classes, using our understanding of virus taxonomies and a priori knowledge of our dataset. This more rigorous evaluation ensures that the classifier does not rely on a collection of over-fitted features and measures the predictive power of the classifier more accurately and in a way that is relevant to the domain of computer viruses. We show that our model performs better than the traditional approach on a test set containing viruses unrelated to any training example, and that it can be expected to perform as well in the real world.
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Paura, Markas. "Sąvokos kompiuterių virusas semantinis laukas." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2014. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2014~D_20141230_153317-55602.
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Sąvoka kompiuterių virusas gyvuoja nuo 1984 m., tačiau net ir praėjus trims dešimtmečiams lietuvių kalboje ji vis dar nėra pakankamai diferencijuota, tebėra painiojama su kitomis kompiuterių saugumui priskiriamomis sąvokomis, dažniausiai kirminu ir Trojos arkliu. Iki šiol nebuvo atlikta išsamių lingvistinių nagrinėjamos sąvokos ir jos žymiklio tyrimų lietuvių kalba. Šios disertacijos tikslas – aprašyti sąvokos kompiuterių virusas semantinį lauką, kurio pagrindas yra termino kompiuterių virusas mikrosistema. Tirta 919 Symantec kompiuterių grėsmių banke Threat Explorer paskelbtų kompiuterių grėsmių aprašų su žyma Virus, Threat Explorer partnerių terminografiniai ištekliai ir Lietuvoje nuo 1984 m. iki 2006 m. išleisti kompiuterijos terminų žodynai bei tuo pačiu laikotarpiu paskelbti analitiniai straipsniai apie kompiuterijos leksiką Lietuvos mokslo leidiniuose. Sąvokos raidai įvertinti įtraukta papildomų terminografinių išteklių lietuvių ir prancūzų kalbomis. Visi surinkti terminologiniai duomenys apie nagrinėjamos sąvokos semantinį lauką, kurį šiame darbe sudaro 177 sąvokos, tirti taikant šiuos metodus: lyginamąjį, aprašomąjį, komponentinės analizės ir aukštynkryptės analizės metodais. Tyrimo metu paaiškėjo, kad disertacijoje nagrinėjamos sąvokos semantinį lauką dėl jį sudarančių sąvokų tarpusavio hierarchinių santykių galima gana tiksliai apibrėžti. Toks semantinių laukų teorijos taikymas terminologiniams duomenims, iš kurių svarbiausiu laikoma intensinė termino apibrėžtis... [toliau žr. visą tekstą]The concept “computer virus” has been in existence since 1984. However despite the fact that almost 30 years have passed, it is not properly defined in Lithuanian sources and is still confused with other concepts tied to computer security, most often with concepts such as “worms” and “Trojan horses.” There has never been comprehensive linguistic research carried out on this concept and its signifier in Lithuanian. The aim of this dissertation is to describe the semantic field of the concept “computer virus,” the basis of which is the microsystem of the term “computer virus.” The following was used for the research: a total of 919 computer threat descriptions included in the Symantec computer threat bank that are tagged virus, the terminographical resources of Threat Explorer partners and computer terminology dictionaries published in Lithuania from 1984 to 2006 as well as analytical articles about computer terminology in Lithuanian scientific journals during the same period. Additional terminographical resources in Lithuanian and French are included in the research to assess and analyze the development of this concept. All of the terminological date that was collected concerning the semantic field of the concept in question (comprised of 177 concepts in this work) was analysed using the following methods: the comparative method, descriptive method, componential analysis and uplink analysis. As the research was carried out, it became clear that the semantic field of the... [to full text]
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Paura, Markas. "Le champ sémantique du concept virus informatique." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2014. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2014~D_20141230_153304-85220.
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Nous avons établi, dans la base des descriptions des menaces informatiques Threat Explorer de Symantec un groupe de descriptions répertoriées virus et nous avons essayé de les traduire en lituanien en nous servant des sources terminographiques qui sont à disposition en lituanien et qui datent de 1971 à 2012. Très vite, nous nous sommes rendus compte qu’un groupe assez important de termes anglais et français désignant différents types de virus informatiques n’avaient pas d’équivalents lituaniens. De même, nous avons observé que, pendant une trentaine d’années de son existence, le concept de virus informatique a toujours été confondu avec d’autres concepts de même niveau tels que ver informatique, ou tout court ver, et cheval de Troie. Ces confusions ont engendré un échec de traduction des descriptions mentionnées précédemment et nous ont ammené vers l’idée de rédiger un travail, la présente thèse, afin d’identifier les raisons de l’impossibilité de nous fier aux sources terminologiques lituaniennes, de les analyser pour ensuite proposer des solutions fondées sur les conclusions d’une étude scientifique.Sąvoka kompiuterių virusas gyvuoja nuo 1984 m., tačiau net ir praėjus trims dešimtmečiams lietuvių kalboje ji vis dar nėra pakankamai diferencijuota, tebėra painiojama su kitomis kompiuterių saugumui priskiriamomis sąvokomis, dažniausiai kirminu ir Trojos arkliu. Iki šiol nebuvo atlikta išsamių lingvistinių nagrinėjamos sąvokos ir jos žymiklio tyrimų lietuvių kalba. Šios disertacijos tikslas – aprašyti sąvokos kompiuterių virusas semantinį lauką, kurio pagrindas yra termino kompiuterių virusas mikrosistema. Tirta 919 Symantec kompiuterių grėsmių banke Threat Explorer paskelbtų kompiuterių grėsmių aprašų su žyma Virus, Threat Explorer partnerių terminografiniai ištekliai ir Lietuvoje nuo 1984 m. iki 2006 m. išleisti kompiuterijos terminų žodynai bei tuo pačiu laikotarpiu paskelbti analitiniai straipsniai apie kompiuterijos leksiką Lietuvos mokslo leidiniuose. Sąvokos raidai įvertinti įtraukta papildomų terminografinių išteklių lietuvių ir prancūzų kalbomis. Visi surinkti terminologiniai duomenys apie nagrinėjamos sąvokos semantinį lauką, kurį šiame darbe sudaro 177 sąvokos, tirti taikant šiuos metodus: lyginamąjį, aprašomąjį, komponentinės analizės ir aukštynkryptės analizės metodais. Tyrimo metu paaiškėjo, kad disertacijoje nagrinėjamos sąvokos semantinį lauką dėl jį sudarančių sąvokų tarpusavio hierarchinių santykių galima gana tiksliai apibrėžti. Toks semantinių laukų teorijos taikymas terminologiniams duomenims, iš kurių svarbiausiu laikoma intensinė termino apibrėžtis... [toliau žr. visą tekstą]
The concept “computer virus” has been in existence since 1984. However despite the fact that almost 30 years have passed, it is not properly defined in Lithuanian sources and is still confused with other concepts tied to computer security, most often with concepts such as “worms” and “Trojan horses.” There has never been comprehensive linguistic research carried out on this concept and its signifier in Lithuanian. The aim of this dissertation is to describe the semantic field of the concept “computer virus,” the basis of which is the microsystem of the term “computer virus.” The following was used for the research: a total of 919 computer threat descriptions included in the Symantec computer threat bank that are tagged virus, the terminographical resources of Threat Explorer partners and computer terminology dictionaries published in Lithuania from 1984 to 2006 as well as analytical articles about computer terminology in Lithuanian scientific journals during the same period. Additional terminographical resources in Lithuanian and French are included in the research to assess and analyze the development of this concept. All of the terminological date that was collected concerning the semantic field of the concept in question (comprised of 177 concepts in this work) was analysed using the following methods: the comparative method, descriptive method, componential analysis and uplink analysis. As the research was carried out, it became clear that the semantic field of the... [to full text]
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Semyonov, S. G., Svitlana Gavrylenko, and Viktor Chelak. "Processing information on the state of a computer system using probabilistic automata." Thesis, Institute of Electrical and Electronics Engineers, 2017. http://repository.kpi.kharkov.ua/handle/KhPI-Press/40752.
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The paper deals with the processing of information about the state of a computer system using a probabilistic automaton. A model of an intelligent system for detection and classification of malicious software is proposed, which compares a set of features that are characteristic for different classes of viruses with multiple states of the machine. The analysis process is reduced to modeling the operation of the automaton taking into account the probability of transition from state to state, which at each step is recalculated depending on the reaction of the environment. The received results of research allow to reach a conclusion about the possibility of using the offered system for detection of the harmful software.
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Martins, Duarte Lima. "Purification of complex biopharmaceuticals with new processes, advanced analytics and computer-aided process design tools." Master's thesis, Faculdade de Ciências e Tecnologia, 2013. http://hdl.handle.net/10362/11105.
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Dissertação para obtenção do Grau de Mestre em
BiotecnologiaViruses are highly efficient vectors that have been used for vaccination and gene therapy applications. However, their complexity renders downstream process particularly challenging since devices and strategies especially designed for virus purification are still lacking or need further optimization. After an introduction to the challenges of virus purification and the current strategies being employed, this dissertation presents the study of three different stages of the downstream process: clarification, ultrafiltration and chromatography. A novel clarification procedure based on diatomaceous earth was evaluated. Small-scale batch incubations led to the identification of Divergan RS – a synthetic non-charged material – as the most promising candidate for integration in a scalable filtration set-up. Ultrafiltration was addressed with the evaluation of cassette and hollow fiber modules. The results obtained show that cassette module with cut-offs in the 500 kDa range and highly hydrophilic materials enable complete recovery of infective Adenovirus while reducing process time in half when compared with the best hollow fibers. Despite the encouraging results with Adenovirus, the experiments using Retrovirus resulted in low yields and possible optimization strategies were identified. Membrane technology was also evaluated as an alternative to the packed-bed chromatography columns. By using a scale-down 96-well device, the impact of ligand density, membrane structure and feed conductivity were evaluated for the purification of Adenovirus by ion exchange chromatography. The hydrogel-grafted membrane with ligand density of 2.4 μmol cm-2 operated in bind/elute mode shown the best compromise between yield and purity. Overall, this thesis contributed to the advancement of virus purification field by exploiting innovative technologies.
Fundação para a Ciência e a Tecnologia - (PTDC/EBBBIO/119501/2010)
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Rüfenacht, Jürg. "Epidemiology of infection with bovine viral diarrhea virus in Switzerland : a study designed by computer modeling /." [S.l.] : [s.n.], 1999. http://www.stub.unibe.ch/html/haupt/datenbanken/diss/bestell.html.
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Muppalla, RoopTeja. "A Twitter-based Study for Understanding Public Reaction on Zika Virus." Wright State University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=wright151994467953523.
Full text
50
Von, Kirchbach Johann Carlo. "In silico analysis of RNA signals and evolutionary constraints in influenza A virus." Thesis, University of Cambridge, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.609825.
Full text