Neste estudo avaliamos o efeito dos AGCC (acetato, propionato e butirato) sobre o recrutamento de neutrófilos e parâmetros funcionais (espécies reativas de oxigênio [ERO], citocinas e óxido nítrico, fagocitose e destruição de C. albicans). Investigamos ainda a ativação do NFkB, efeito sobre histonas desacetilases (HDAC) e GPR43. Acetato e butirato alteraram a produção de ERO; o primeiro aumentou a produção de peróxido de hidrogênio, enquanto o butirato inibiu a produção estimulada por PMA. O butirato reduziu a fagocitose e killing de leveduras. Propionato e butirato reduziram a produção de TNF-<font face=\"Symbol\">&#945, CINC-2<font face=\"Symbol\">&#945<font face=\"Symbol\">b e óxido nítrico e aumentaram a síntese de IL-1<font face=\"Symbol\">&#946 por neutrófilos estimulados com LPS. Esses efeitos decorreram de ação a nível transcricional e devem envolver inibição da atividade de HDAC e da ativação do NFkB. Os AGCC aumentaram a migração de neutrófilos in vitro e in vivo. Esses efeitos decorreram de aumento da produção de CINC-2<font face=\"Symbol\">&#945<font face=\"Symbol\">b pelo tecido e da ação direta dos AGCC via GPR43. Os AGCC apresentam ações pró- e antiinflamatórias dependendo do parâmetro analisado. / We evaluated the effect of SCFA (acetate, propionate and butyrate) on the recruitment of neutrophils and functional parameters (reactive oxygen species [ROS], cytokines and nitric oxide production, phagocytosis and destruction of C. albicans). We also investigated the activation of NFkB, effect on histone deacetylases (HDAC) and GPR43. Acetate and butyrate altered the production of ROS, the former increased the production of hydrogen peroxide, whereas butyrate inhibited the production stimulated by PMA. Butyrate reduced the phagocytosis and killing of yeast. Propionate and butyrate reduced the production of TNF-<font face=\"Symbol\">&#945, CINC-2<font face=\"Symbol\">&#945<font face=\"Symbol\">b and nitric oxide and increased the synthesis of IL-1<font face=\"Symbol\">&#946 by LPS-stimulated neutrophils. These effects involve modification at the transcriptional level and inhibition of HDAC and NFkB activation. SCFA increased neutrophil migration in vitro and in vivo, an effect that may be the result of increased production of CINC-2<font face=\"Symbol\">&#945<font face=\"Symbol\">b and direct action of GPR43. SCFA present pro- and anti-inflammatory actions depending on the parameter analyzed.

This master's thesis deals with open source PBX security against security attacks. In the theoretical part is detailed description of problematic about attacks that could be used on VoIP systems with high focus on the Denial of Service attack. Furthermore are in theoretical part described methods of security of initialization protocol SIP. Individual chapter is devoted to intrusion detection and prevention of IDS and IPS systems, focusing on Snort and OSSEC. In the practical part of the work was created generator of attacks against various PBX systems, which was subsequently used for detailed testing. Special tests of PBX system are then used against DoS attacks, for which was created protection in form of active elements consisting of IDS Snort & OSSEC. These are capable to provide protection in real-time. The protection was tested on particular PBX systems and in matter of comparison were measured possibilities before and after of security implementation. The output of this work is attacks generator VoIPtester and creation of configuration rules for Snort and OSSEC.

In this dissertation, we describe the portable, open-source distributed simulation framework (WINDS) targeting simulations of wireless network infrastructures that we have developed. We present the simulation framework which uses modular architecture and apply the framework to studies of mobility pattern effects, routing and intrusion detection mechanisms in simulations of large-scale wireless ad hoc, infrastructure, and totally mobile networks. The distributed simulations within the framework execute seamlessly and transparently to the user on a symmetric multiprocessor cluster computer or a network of computers with no modifications to the code or user objects. A visual graphical interface precisely depicts simulation object states and interactions throughout the simulation execution, giving the user full control over the simulation in real time. The network configuration is detected by the framework, and communication latency is taken into consideration when dynamically adjusting the simulation clock, allowing the simulation to run on a heterogeneous computing system. The simulation framework is easily extensible to multi-cluster systems and computing grids. An entire simulation system can be constructed in a short time, utilizing user-created and supplied simulation components, including mobile nodes, base stations, routing algorithms, traffic patterns and other objects. These objects are automatically compiled and loaded by the simulation system, and are available for dynamic simulation injection at runtime. Using our distributed simulation framework, we have studied modern intrusion detection systems (IDS) and assessed applicability of existing intrusion detection techniques to wireless networks. We have developed a mobile agent-based IDS targeting mobile wireless networks, and introduced load-balancing optimizations aimed at limited-resource systems to improve intrusion detection performance. Packet-based monitoring agents of our IDS employ a CASE-based reasoner engine that performs fast lookups of network packets in the existing SNORT-based intrusion rule-set. Experiments were performed using the intrusion data from MIT Lincoln Laboratories studies, and executed on a cluster computer utilizing our distributed simulation system.

No description available.

In this time of increasing cyber risks, robust intrusion detection systems (IDS) arefundamentally necessary for protecting network systems. This master thesis compares twoprimary network intrusion detection resources to clarify their effectiveness, advantages, andboundaries. The investigation follows a thorough approach, including reviewing existingliterature, practical experimentation, and assessing their performance. The primary goal revolves around a deeper comprehension of the operational procedures, threatdetection capacity, and scalability of the chosen IDS solutions. Through carefulexperimentation and scrutiny, this study investigates various elements such as detection accuracy, false favorable rates, the usage of resources, and resilience in varied networksituations. Real-life data sets and contrived attack situations are harnessed to measure the proficiency of these tools in identifying both identified and fresh intrusion efforts. Finally, our experimentation did not identify a single optimal tool due to certain imperfections in both evaluated tools. However, these findings were instrumental in concluding the properties that would constitute an ideal tool. In the end, this study propels the forward arena of networksecurity, offering a detailed insight into the capabilities and limitations of day-to-day intrusion detection tools. This study aims to strengthen cybersecurity defenses and nurture improved decision-making capabilities. These efforts mitigate the constantly changing threats caused byharmful entities in our digital world.

This is a report on the possibility of using a Raspberry Pi as an intrusion detection system in a home environment to increase network security. The focus of this study was on how well two different generations of Raspberry Pi would be able to  handle network traffic while acting as an intrusion detection system. To examine this a testing environment was set up containing two workstation computers connected to a Raspberry Pi, each computer hosting a virtual machine. Tests measuring the network throughput as well as the CPU and memory usage were performed on each of the Raspberry Pi devices. Two models of Raspberry Pis were used; Raspberry Pi model B+ and Raspberry Pi 2 model B; each of them running the operating system Arch Linux ARM. The results of these tests were that both of the Raspberry Pis could be used as an intrusion detection system but has some limitations that could impede usage depending on the requirements of the user. Raspberry Pi 2 model B show benefits of its updated hardware by suffering lower throughput degradation than Raspberry Pi model B+, while using less of it's total CPU and memory capacity. / Den här rapporten behandlar möjligheten att använda en Raspberry Pi som ett intrångdetekteringssystem i en hemma miljö för att öka nätverkssäkerheten. Fokusen i den här studien ligger på hur väl de två senaste generationerna av Raspberry Pi skulle kunna hantera nätverkstrafik samtidigt som den undersöker nätverkstrafiken och söker efter hot. För att kontrollera hur väl en Raspberry Pi kan fungera som ett intrångdetekteringssystem har en laborationsmiljö upprättats bestående av två fysiska maskiner som vardera används för att virtualisera en virtuell maskin. Tester för att mäta datagenomströmning, processor och minnesbelastning utfördes på var och en av Raspberry Pi. Två modeller av Raspberry Pi användes; Raspberry Pi model b+ och Raspberry Pi 2 model b, både körde operativsystemet Arch Linux ARM. Resultatet av testerna visade att det går att använda båda enheterna för att upprätta ett intrångdetekteringssystem, men det finns vissa begränsningar i enheterna vilket kan begränsa implementationsmöjligheterna. Raspberry Pi 2 model B uppvisade bättre resultat i form av att den är lägre belastad och har en högre datagenomströmning till skillnad från Raspberry Pi model B+. Raspberry Pi 2 model B har nyare och snabbare hårdvara vilket är den troliga orsaken till att den presterar bättre.

The threat against industrial networks have increased, which raises the demands on the industries cybersecurity. The industrial networks are not constructed with cybersecurity in mind, which makes these systems vulnerable to attacks. Even if the networks outer protection is deemed sufficient, the system may still be infected. This risk demands an intrusion detection system (IDS) that can identify infected components. An IDS scans all traffic of a point in the network and looks for traffic matching its detections parameters, if a match is made the IDS will send an alarm to the administrators. It can also analyze the network traffic using a behavior based method which means that the IDS will alert administrators if network activity deviates from the normal traffic flow. It is of vital essence that the IDS do not impair with the system, an outage of the industrial process can have a high cost for the industry. This report aims to put forward plans for the implementation of an IDS in one of Mälarenergi AB’s industrial networks, this will be made using the Bro and Snort intrusion detection systems. / Hoten mot industrinätverken har blivit större vilket har ställt högre krav på industriernas cybersäkerhet. Industrinätverk är ofta inte konstruerade med cybersäkerhet i åtanke, vilket har gjort dessa system sårbara mot attacker. Även om nätverkets yttre skydd anses gott går det inte att vara säker på att ett industrinätverk förblir osmittat. Detta ställer krav på någon form av intrångsdetekteringssystem (IDS) som kan upptäcka infekterad utrustning och suspekt datatrafik i nätverket. En IDS skannar alla paket vid en viss punkt i nätverket, om IDS:en upptäcker något paket som matchar med dess signatur kommer den att larma en administratör. IDS:en kan även använda beteendeanalys där den larmar om nätverksaktiviteten avviker från det normala. Det är mycket viktigt att en IDS inte orsakar avbrott i industriprocessen, om en process stannar kan det innebära stora kostnader för industrin. Denna rapport syftar till att lämna ett lösningsförslag på en IDS-implementation till ett av Mälarenergi AB: s processnätverk, lösningen konstruerades med hjälp av IDS:erna Bro och Snort. / <p>Vissa bilder i den elektroniska rapporten har tagits bort av upphovrättsliga skäl. Författarna har bedömt att rapporten är förståelig även utan dessa bilder. </p>

Submitted by Patrícia Cerveira (pcerveira1@gmail.com) on 2017-06-07T20:29:49Z No. of bitstreams: 1 Henrique_Fernandes Dissertação.pdf: 2826928 bytes, checksum: f7388a5396e90a8444a4aac05feada53 (MD5) / Approved for entry into archive by Biblioteca da Escola de Engenharia (bee@ndc.uff.br) on 2017-07-03T14:05:51Z (GMT) No. of bitstreams: 1 Henrique_Fernandes Dissertação.pdf: 2826928 bytes, checksum: f7388a5396e90a8444a4aac05feada53 (MD5) / Made available in DSpace on 2017-07-03T14:05:51Z (GMT). No. of bitstreams: 1 Henrique_Fernandes Dissertação.pdf: 2826928 bytes, checksum: f7388a5396e90a8444a4aac05feada53 (MD5) / Os Sistemas de Detecção e Prevenção de Intrusão são fundamentais para a segurança da rede de computadores, inspecionar o tráfego da rede em tempo real em busca de intrusos para garantir uma rede confiável é um dos seus papéis. Porém a falta de integração com os ativos da rede é um dos principais fatores que limitam sua atuação. O conceito de Redes Definidas por Software visa diminuir a falta de integração entre os ativos de rede devido a separação do plano de dados do plano de controle. Diante da limitação da integração entre os ativos de redes e os Sistemas de Detecção e Prevenção de Intrusão, o presente estudo propõe, desenvolve e demonstra o IDSFlow, um modelo de integração de sistemas de detecção de intrusão em redes definidas por software. Para validar o IDSFlow, foram realizados testes utilizando o Openflow, o Mininet, CPqD e o Snort. Os resultados obtidos pelos algorítimos desenvolvidos e apresentados mostram a capacidade de integração proposta, é possível verificar a viabilidade de utilizar as regras já existentes e funcionais para o Snort assim como utilizar o histórico de utilização da rede para aumentar a efetividade da detecção e dos bloqueios de intrusos. / Intrusion Detection and Prevention Systems are fundamental to the network security, to inspect the traffic in real time seeking intruders to ensure a reliable network is one of it’s roles. However the lack of integration between the network equipments, is one of the biggest factors to limit its operations. The concept of Software Defined Networks aims to reduce the lack of integration among network assets due to the separation of the data plan from the control plan. Given the limitation of integration between networks assets and Intrusion Detection and Prevention Systems, the present study proposes, develops and demonstrates IDSFlow, an integration model of intrusion detection systems in softwaredefined networks. To validate IDSFlow, tests were run using Openflow, Mininet, CPqD and Snort. The results obtained by the algorithms developed and presented show the proposed integration capacity, it is possible to verify the feasibility of using the existing and functional rules for Snort as well as to use the network usage history to increase the effectiveness of intrusion detection and block.