[Abstract] It becomes more common that powerful computer viruses infect PCs and servers easily since Internet has emerged. The quick evolution of virus types, from simple macro virus to Spam mail virus such as Melissa, to hybrid virus with cracker features such as CodeRed and Nimda, has driven enterprises or end users to severe security panic from time to time. Could pure antivirus companies survive under more complicated computer security requirement? The top 3 antivirus companies in the world, Symantec¡BNetwork Associates and Trend Micro, according to Gartner Group¡¦s research, adopt different strategies to face strict security challenge. NAI fell from top spot due to its failure one-stop-shopping strategy, which now is executed again by Symantec. However Symantec becomes number one antivirus company in the world (IDC 2001 report). It turns out that the success DNA of antivirus company must contain innovation capability and vision. Trend Micro earns number three of world antivirus company based on her strong innovation and vision. Will Trend Micro¡¦s focus strategy ¡§Best-of-Breed¡¨ which is the major differentiation with other two competitors, Symantec and NAI, keep Trend competitive in the AV market? I will discuss this topic in this thesis.

War between malware and antimalware software started two decade back and have adopted the modern techniques with the evolution of technological development in the field of information technology. This thesis was targeted to analyze the performance of freeware antivirus programs available in the market. Several tests were performed to analyze the performance with respect to the core responsibilities of these software’s to scan and detect the viruses and also prevent and eradicate form them. Although irrelevant for common users may be but very important for technical professionals, many tests were performed to analyze the quality of these softwares with respect to their effects on the system it-self like utilization and engagement of precious resources, processing times and also system slowdown because of monitoring techniques. The results derived from these tests show not only the performance and quality of these softwares but also enlighten some areas to be focused for further analysis.

Šiame darbe apžvelgti kompiuterių virusų tipai ir pateiktos jų klasifikacijos bei apžvelgta kita kenkėjiška programinė įranga. Darbe yra pateiktos pagrindinės kovos su virusais priemonės ir apžvelgti pagrindiniai kompiuterių virusų paieškos metodai. Buvo išanalizuoti antivirusinių programų veikimo principai, ypatumai ir pagrindinės jų sudedamos dalys. Pateikti reikalavimai šiuolaikinėms antivirusinėms programoms bei atskleista programų problematika. Atlikus anketinę apklausą buvo išryškintos populiariausios nemokamos ir mokamos antivirusinės programos. Apžvelgus antivirusinių testavimo laboratorijų programų vertinimo kriterijus ir naudojamus testus buvo parinkti testai skirti antivirusinių programų poveikio kompiuterio darbui ištirti. Atlikus eksperimentus naudojant pasirinktus testus buvo nustatytas populiariausių antivirusinių programų poveikis kompiuterio darbui ir pagrindinių kompiuterio vartotojo veiksmų atlikimo greičiui. Taipogi buvo palygintas mokamų ir nemokamų antivirusinių programų poveikis kompiuterio darbui. / Computer viruses types and several classifications of viruses were reviewed in this work. The main actions of struggle with computer viruses and main methods for searching viruses were presented in this work. Main constituent parts and features of antivirus programs were analyzed too. The requirements for modern antivirus programs were introduced and problems with antivirus programs were described in this work. The questioning was performed and the most popular free and fee-paying antivirus programs were discovered. Tests for antivirus programs of antivirus testing laboratories were reviewed, and tests for examination influence of antivirus programs on computer performance were chosen. The experimental investigations using chosen tests were performed and the influence of antivirus programs on computer performance was found out. The comparison free and fee paying antivirus programs according to influence on computer performance was made.

Malware is a fast growing threat that consists of a malicious script or piece of software that is used to disrupt the integrity of a user's experience. Antivirus software can help protect a user against these threats and there are numerous vendors users can choose from for their antivirus protection. However, each vendor has their own set of virus definitions varying in resources and capabilities in recognizing new threats. Currently, a persistent system is not in place that measures and displays data on the performance of antivirus vendors in responding to new malware over a continuous period of time. There is a need for a system that can evaluate antivirus performance in order to better inform end users of their security options, in addition to informing clients of prevalent threats occurring in their network. This project is dedicated to assessing the viability of a cloud sourced malware reporting framework that uses distributed agents to evaluate the performance of antivirus software based on malware signatures.

Im Rahmen dieser Studienarbeit wird untersucht, welche Lösungen es momentan zur Filterung von Email mit unerwünschten Schadensfunktionen auf Mailservern gibt. Dabei werden sowohl offene als auch proprietäre Lösungen betrachtet und die momentanen Randbedingungen der TU Chemnitz beachtet.

I denna uppsats avser författaren att utvärdera om det är möjligt för en hemanvändare attskapa en trojan med ett program som genererar trojaner och med hjälp av andra gratisverktyg ta sig förbi antivirus-program. Samtidigt så kommer antivirus-program utvärderas angående hur dem lyckas skydda sig mot de skapade trojanerna och ge en överblick om hur skyddet är, både via uppladdning av trojaner till VirusTotal samt test av olika antivirusprogram. Den vetenskaplig forskning som gjorts tidigare som denna uppsats kommer vara snarlikgår att finna i [5]. Det forskas även om nya idéer för att upptäcka trojaner redan när dembörjar kommunicera[4] Uppsatsens resultat består av tre delar, resultat av uppladdning av trojaner viaVirusTotal, resultat av skanning med antivirus-program samt en kort analys omresultaten. I resultatet om VirusTotal så får en överblick om hur antivirus-programupptäcker Remote Access Trojaner(RAT) som blivit genererade i ett program.Dessa RATs görs även mer svårupptäckta av verktyg som går att få tag i gratis, cryptersför att kryptera trojanerna och binders för att binda trojaner ihop med en annan fil. Efterantivirus-skanningen redovisas resultat om hur ett antal utvalda antivirus-program klararav att skydda en PC mot RATs. I resultaten upptäcktes det att säkerheten är i vissa fallganska undermålig, men att det även finns antivirus-program som skyddar betydligtbättre än andra.

Mestre -- Escola Nacional de Saude Publica, Rio de Janeiro, 2002.

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / Muitos compostos isolados de plantas apresentam diversos tipos de atividades biolÃgicas, como tem sido o caso de proteÃnas conhecidas como lectinas. Essas proteÃnas fazem parte de um grupo de molÃculas que reconhecem e se ligam a carboidratos contidos na superfÃcie das cÃlulas de forma especÃfica e reversÃvel. Nas Ãltimas dÃcadas as lectinas vÃm se tornando ferramentas promissoras com aÃÃo antitumoral e antiviral. Esse trabalho objetivou investigar a possÃvel aÃÃo anticancerÃgena e antiviral das lectinas isoladas das sementes de Canavalia brasiliensis (ConBr), Canavalia marÃtima (ConM), Dioclea lasiocarpa (DLasiL) e Dioclea sclerocarpa (DSclerL), o possÃvel mecanismo inicial de aÃÃo anticancerÃgena da lectina DLasiL, alÃm de estudar a estrutura da DLasiL atravÃs das tÃcnicas de fluorescÃncia e dicroÃsmo circular e seu mecanismo para atividade anticÃncer. A lectina DLasiL foi particularmente caracterizada, apresentando 237 resÃduos de aminoÃcidos com alta similaridade com as lectinas da subtribo Diocleinae. RessonÃncia paramagnÃtica de elÃtrons mostrou sinal caracterÃstico da presenÃa do Ãon manganÃs (Mn2+), enquanto medidas de ICP-MS confirmaram a quantidade deste Ãon, alÃm de cÃlcio (Ca2+), cuja quantidade foi inferior ao medido nas outras lectinas. Estudos de fluorescÃncia intrÃnseca indicaram melhor acessibilidade aos triptofanos por molÃculas neutras, provando que a vizinhanÃa possuui carÃter nÃo carregado, enquanto que fluorescÃncia extrÃnseca usando Bis-ANS ilustrou a alteraÃÃo conformacional provocada pela interaÃÃo a aÃÃcares, concluindo que à possÃvel utilizar esse tipo de medida para a constataÃÃo desse fenÃmeno. Medidas de DicroÃsmo Circular confirmam a significativa estabilidade tÃrmica da DLasiL no qual perdeu 50% de sua atividade a 72 oC. Para investigar a aÃÃo antitumoral das lectinas em estudo, cÃlulas de carcinoma de ovÃrio humano (A2780), carcinoma caucasiano de pulmÃo humano (A549), carcinoma de mama humano (MCF7), carcinoma de prÃstata humano (PC3) foram cultivadas com DLasiL. AlÃm disso, foi determinada a viabilidade celular. Os resultados mostraram que as lectinas foram efetivas em inibir o crescimento celular das linhangens testadas utilizando concentraÃÃo nanomolar. Dentre as lectinas testadas, a mais efetiva em inibir o crescimento celular foi a DLasiL, demonstrando um maior Ãndice de citotoxicidade contra cÃlulas da linhagem A2780 com IC50 de 52 nM. O mecanismo de aÃÃo da DLasiL foi investigado atravÃs de ensaios especÃficos de apoptose. Dados de ciclo celular mostraram que a DLasiL apresenta mudanÃas significativas nos nÃveis S e G2/M. Adicionalmente, ensaios com uma sÃrie de conjuntos de vÃrus apresentaram resultados bastante promissores. / Several compounds isolated from plants, including proteins called lectins, have exhibited many types of biological activities. These proteins are specific recognizing and binding to carbohydrates found onto the cell surface. During the last decades, lectins have become promising sources for antitumor and antiviral studies. This study aimed to investigate legumineous lectins, ConBr (Canavalia brasiliensis), ConM (Canavalia maritima), DLasiL (Dioclea lasiocarpa) and DSclerL (Dioclea sclerocarpa) as potential anti-cancer and anti-viral agents, as well as studying structurally DLasiL using fluorescence, circular dichroism and its initial mechanism of anticancer activity. DLasiL lectin was characterized showing 237 amino acid residues with high similarity to lectin from the Diocleinae subtribe. Electron paramagnetic resonance of DLasiL showed a typical signal for manganese (Mn+2), while ICP-MS provided its actual amount along with calcium (Ca2+), whose values were below those found for the other lectins. Intrinsic fluorescence studies using three quenchers showed a better accessibility of neutral species to tryptophans of DLasiL, while extrinsic fluorescence using bis-ANS exhibited a dose-dependent conformational changes promoted by sugars. Circular dichroism showed very expressive thermal stability of DLasiL with mid-point for thermal denaturation at 72 ÂC. These lectins were used to treat human ovarian carcinoma (A2780), Human Lung Carcinoma (A549), Human Breast Carcinoma (MCF7), Human Prostate Carcinoma (PC3) and cell viability was determined. These proteins showed potent activity on inhibiting cell growth at nanomolar concentrations. Among these lectins, DLasiL was the most effective showing potent cytotoxicity against A2780 cell line with IC50 of 52 nM. The mechanism of cytotoxicity action of DLasiL was investigated by specific apoptosis assay. Cell cycle studies showed DLasiL causes significant changes in the levels of S and G2/M. A virus screening investigation was carried out showing promissing antiviral activity.

Nowadays, malware attacks are increasing day by day, and are an ongoing problem for many entities (e.g. companies, institutions). One of the ways to prevent malware is by using tools such as an antivirus. Indeed, antivirus vendors have created databases containing malware data that are used to detect malware. However, the traditional way to store data is filled with many issues due to its centralized structure, which leads to having a single-point-of-failure. This project aims to answer the challenge of having a centralized structure for storing and sharing data through a system architecture using Design Science Methodology. Throughout the project an implementation of the system architecture has been developed, which lead to having a prototype named HuntChain. It is an on-demand scanning interface, which introduces a decentralized approach (through Blockchain Technology) for storing and sharing malware data, while still having the possibility to detect malware. This prototype has been evaluated in an artificial environment, which demonstrated the fulfillment of the requirements. The artefact also solves the issue of having antivirus databases overlapping with each other, which is a waste of resources. Finally, HuntChain has been developed with the idea that it has to be available to anyone, where any developer could improve, modify, and/or add new functionalities, therefore, it is available on GitHub as an open-source project.

Background Efficacy and safety of treatments for hospitalized COVID-19 are uncertain. We systematically reviewed efficacy and safety of remdesivir for the treatment of COVID-19. Methods Studies evaluating remdesivir in adults with hospitalized COVID-19 were searched in several engines until August 21, 2020. Primary outcomes included all-cause mortality, clinical improvement or recovery, need for invasive ventilation, and serious adverse events (SAEs). Inverse variance random effects meta-analyses were performed. Results We included four randomized controlled trials (RCTs) (n = 2296) [two vs. placebo (n = 1299) and two comparing 5-day vs. 10-day regimens (n = 997)], and two case series (n = 88). Studies used intravenous remdesivir 200mg the first day and 100mg for four or nine more days. One RCT (n = 236) was stopped early due to AEs; the other three RCTs reported outcomes between 11 and 15 days. Time to recovery was decreased by 4 days with remdesivir vs. placebo in one RCT (n = 1063), and by 0.8 days with 5-days vs. 10-days of therapy in another RCT (n = 397). Clinical improvement was better for 5-days regimen vs. standard of care in one RCT (n = 600). Remdesivir did not decrease all-cause mortality (RR 0.71, 95% CI 0.39 to 1.28, I2 = 43%) and need for invasive ventilation (RR 0.57, 95%CI 0.23 to 1.42, I2 = 60%) vs. placebo at 14 days but had fewer SAEs; 5-day decreased need for invasive ventilation and SAEs vs. 10-day in one RCT (n = 397). No differences in all-cause mortality or SAEs were seen among 5-day, 10-day and standard of care. There were some concerns of bias to high risk of bias in RCTs. Heterogeneity between studies could be due to different severities of disease, days of therapy before outcome determination, and how ordinal data was analyzed. Conclusions There is paucity of adequately powered and fully reported RCTs evaluating effects of remdesivir in hospitalized COVID-19 patients. Until stronger evidence emerges, we cannot conclude that remdesivir is efficacious for treating COVID-19. / Revisión por pares