Syn Attack Research Articles

On the Protection of a High Performance Load Balancer Against SYN Attacks** This is an extended journal version of [2

SYN flooding is a simple and effective denial-of-service attack. In this attack, many TCP SYN requests are sent to the targeted server, in an attempt to consume its resources and make it unresponsive to legitimate traffic. While SYN attacks have traditionally targeted web servers, they are also known to be very harmful to intermediate cloud devices, and in particular to stateful load balancers (LBs). Fighting against a SYN attack without negatively affecting legitimate connections is not easy, especially if the LB needs to perform frequent server pool updates during the attack, which is very likely since attacks can often last for many hours or even days. This paper is the first to propose LB schemes that guarantee high throughput of one million connections per second, while supporting a high pool update rate without breaking connections and fighting against a high rate SYN attack. Using an analysis and a proof of concept, we show that the LB can handle up to 10 million fake SYNs per second when the RTT is 10ms, and up to 5 million fake SYNs per second when the RTT is 20ms.

Identification of Mirai Botnet in IoT Environment through Denial-of-Service Attacks for Early Warning System

The development of computing technology in increasing the accessibility and agility of daily activities currently uses the Internet of Things (IoT). Over time, the increasing number of IoT device users impacts access and delivery of valuable data. This is the primary goal of cybercriminals to operate malicious software. In addition to the positive impact of using technology, it is also a negative impact that creates new problems in security attacks and cybercrimes. One of the most dangerous cyberattacks in the IoT environment is the Mirai botnet malware. The malware turns the user's device into a botnet to carry out Distributed Denial of Service (DDoS) attacks on other devices, which is undoubtedly very dangerous. Therefore, this study proposes a k-nearest neighbor algorithm to classify Mirai malware-type DDOS attacks on IoT device environments. The malware classification process was carried out using rapid miner machine learning by conducting four experiments using SYN, ACK, UDP, and UDPlain attack types. The classification results from selecting five parameters with the highest activity when the device is attacked. In order for these five parameters to be a reference in the event of a malware attack starting in the IoT environment, the results of the classification have implications for further research. In the future, it can be used as a reference in making an early warning innovative system as an early warning in the event of a Mirai botnet attack.

Anomaly detection framework to prevent DDoS attack in fog empowered IoT networks

Internet of things or in short IoT is a network of interconnected entities such as computing devices, mechanical machines, digital gadgets etc. Cloud based IoT infrastructures are susceptible to Distributed Denial of Service (DDoS) attacks. A DDoS attack may render the server useless for a long period of time causing the services to crash due to extensive load. In this project we will try to introduce the concept of fog computing and try to explain its importance in a 3-tier architecture. We have proposed an anomaly detection architecture for IoT networks where the detection actually happens on the fog layer. The algorithm is based on the CRPS metric which is a single variable algorithm which is the case in most statistical algorithms. Therefore, we have proposed a way to use multiple variables and shown why it is required in a heterogeneous network like IoT. For detection purposes(testing data) we have used Week 5 Day 1 data of DARPA 99 as it contains a TCP SYN attack initiated once for a duration of 6 min 51 s and for ICMP Week 4 Day 1 data of DARPA 99 is used it has 2 attacks for 1s each. The algorithm is able to identify these attacks correctly.

Analysis of denial of service attack on web security systems

In this study, an analysis of the Web security system from a Denial-of-Service Attack (DoS) with SYN Attack, Ping of Death, Land Attack, Smurf Attack and UDP Flood types. The server computer that will be tested for DoS attacks is a local web server including humpuss.com IP: 54.169.71.56, horasindo.com IP: 104.152.168.14, kinarsih.com IP: 156.67.210.132, padanglws.co.id IP: 202.162. 207,101 and arianaas.com with IP Address 213.136.83.52 port 80. The attack on the local web server computer was carried out through attacking cloned computers as many as 5 zombie computers and then observing data traffic on each Web server computer. The test results use ping to the local web server computer, where the target web server sends a replay request time out and the check results in the Google Chrome browser are slow to inaccessible conditions. Ping access time the greater the packet, the greater the average time when accessing a local web server with 5,000 packets is 242.68 seconds, 10,000 packets is 310.28 seconds, 20,000 packets are 337.4 seconds, 30,000 packets are 377.2 seconds, 40,000 packets are 398.4 seconds, 50,000 packets are 545.4 seconds and 100,000 packets are above 600 seconds with the condition that the web server will recover after 600 seconds where the system recovery process depends on each local web server.

Evaluation of Data Center Network Security based on Next-Generation Firewall

This study aims to create a network security system that can mitigate attacks carried out by internal users and reduce attacks from internal networks. Further, a network security system is expected to overcome the difficulty of mitigating attacks carried out by internal users. The goal of this research is to analyze the effectiveness of the Next-Generation Firewall implemented to improve network security. The method used in this research is the comparison method with a test of TCP SYN attack, UDP flood attack, ICMP smurf attack, and DHCP starvation attack on a company network. From the experiment results, it can be concluded that the Next-Generation Firewall has significantly better performance for protecting mitigating attacks carried out by internal users on a company network. It can increase the security of data communication networks against threats from the internal networks.

Structural and functional aspects of mannuronic acid–specific PL6 alginate lyase from the human gut microbe Bacteroides cellulosilyticus

Alginate is a linear polysaccharide from brown algae consisting of 1,4-linked β-d-mannuronic acid (M) and α-l-guluronic acid (G) arranged in M, G, and mixed MG blocks. Alginate was assumed to be indigestible in humans, but bacteria isolated from fecal samples can utilize alginate. Moreover, genomes of some human gut microbiome–associated bacteria encode putative alginate-degrading enzymes. Here, we genome-mined a polysaccharide lyase family 6 alginate lyase from the gut bacterium Bacteroides cellulosilyticus (BcelPL6). The structure of recombinant BcelPL6 was solved by X-ray crystallography to 1.3 Å resolution, revealing a single-domain, monomeric parallel β-helix containing a 10-step asparagine ladder characteristic of alginate-converting parallel β-helix enzymes. Substitutions of the conserved catalytic site residues Lys-249, Arg-270, and His-271 resulted in activity loss. However, imidazole restored the activity of BcelPL6-H271N to 2.5% that of the native enzyme. Molecular docking oriented tetra-mannuronic acid for syn attack correlated with M specificity. Using biochemical analyses, we found that BcelPL6 initially releases unsaturated oligosaccharides of a degree of polymerization of 2–7 from alginate and polyM, which were further degraded to di- and trisaccharides. Unlike other PL6 members, BcelPL6 had low activity on polyMG and none on polyG. Surprisingly, polyG increased BcelPL6 activity on alginate 7-fold. LC–electrospray ionization–MS quantification of products and lack of activity on NaBH4-reduced octa-mannuronic acid indicated that BcelPL6 is an endolyase that further degrades the oligosaccharide products with an intact reducing end. We anticipate that our results advance predictions of the specificity and mode of action of PL6 enzymes.

Performance Analysis Of Firewall As Virtualized Network Function On VMware ESXi Hypervisor

Virtualization technology is slowly being used to build network infrastructure called Network Function Virtualization (NFV). It takes network functions such as firewall, load balancer, IPS out of its hardware then use its software to be run on high specification server. It helps reduce vendor lock-in and help create a multiplatform network function environment. It has a lot of benefits compared to a traditional network. One of them is it can reduce the number of hardware that is used in the telecom industry. This technology runs on the hypervisor that is used for the management of hardware. One of the important components from NFV is Virtualized Network Function (VNF). In NFV, network devices are run on a server so that a firewall is needed because if an attack occurs on the network it will interfere with existing network components. This paper focuses on analyzing the performance of two firewall system, pfSense, and FortiGate. Both firewalls will run on the VMware ESXi hypervisor. It aims to determine the firewall performance comparison in normal conditions without attacks and under SYN DoS attacks. We also evaluate firewall failover capabilities. Based on the results of testing obtained that overall FortiGate has better performance. It has better ability in handling DoS SYN attack because it has lower throughput performance degradation and better FTP performance compare to pfSense. We conclude that FortiGate has best performance compare with pfSense

Cobalt-Catalyzed Stereoselective Synthesis of 2,5- trans-THF Nitrile Derivatives as a Platform for Diversification: Development and Mechanistic Studies.

A straightforward protocol integrating a sustainable approach for the synthesis of new 2,5- trans-THF nitrile derivatives enabling an easy diversification of its side chain scaffolds is described. The reaction tolerated different aromatic and alkyl substituents, affording the corresponding 2,5- trans-THFs in high diastereoselectivity. A detailed mechanistic study using DFT calculation reveals details of the ligand-exchange step, suggesting an inner-sphere syn attack to form the 2,5- trans stereochemistry as the most likely pathway, excluding the previous cation radical intermediate. The formation of a Co-C intermediate is suggested on the basis of the homolytic cleavage to give the previously proposed free carbon radical intermediate.

Rule Generation for TCP SYN Flood attack in SIEM Environment

Security Information and Event Management (SIEM) is a combination of Security Information Management and Security Event Management. SIEM helps in the collection of events from heterogeneous devices and ordering into Common Event Format. The events collected are correlated and observed for changes in the system behaviour. Homogeneous Events such as DoS/Probe attacks can be detected by monitoring single event source. In this paper, TCP SYN flood attack is considered. RETE algorithm is applied on the network event attributes to formulate the rules and stored in database. An alert is triggered, when the rule for TCP SYN attack is matched.

Hydrosilylation of Carbonyls Catalyzed by the Rhenium(V) Oxo Complex [Re(O)(hoz)2]+—A Non-Hydride Pathway

Catalytic conversion of silane and carbonyls by the cationic rhenium oxo complex [Re(O)(hoz)2]+ (1; hoz = 2-(2′-hydroxyphenyl)-2-oxazoline(1−)) was examined using density functional theory. It is shown that complex 1 catalyzed the carbonyl hydrosilylation via a non-hydride pathway—the ionic hydrogenation mechanism. The complete catalytic cycle is proposed to involve three steps: the formation of cis η1-silane Re(V) adduct, the heterolytic cleavage of a Si–H bond through anti attack of carbonyls at the cis η1-silane Re(V) adduct, and transfers between the rhenium and activated silylcarbonium ion to produce the silyl ether product and regenerate catalyst 1. The σ-bond metathesis like transition state suggested by Abu-Omar, although not located, can be inferred from the ionic hydrogenation transition states (TS_3syn and TS_5syn, in which the carbonyls syn attack the η1-silane Re(V) adduct) associated with the higher energy barrier.

TCP SYN‐based DDoS attack on EKG signals monitored via a wireless sensor network

AbstractInternet distributed denial of service (DDoS) attacks are known to exhaust computing resources of a computer. In many cases, even if the attack is not sufficiently strong to completely crash a computing system, its adverse effects can be devastating for the information being processed on the system. When such information is too critical as an electrocardiogram (EKG) signal, the signal itself becomes vulnerable to such attacks also. In this experimental paper, we evaluate the adverse effects of TCP SYN‐based DDoS attacks on EKG signals remotely collected by using wireless sensor networks (WSNs). In lab, we deployed two applications (Serial Forwarder and Oscilloscope GUI) to display the EKG signal on remote monitoring station. Such EKG signal was delivered by a WSN (motes running a modified version of OscilloscopeRF with an analog channel enabled and TOSBase) to collect and send the EKG data. It was found that even though the computing resource of the remote computer running the applications to display the EKG signals was almost exhausted under a DDoS attack, the system was still responding (alive) and displaying the collected EKG signal. However, the normal EKG signal pattern was distorted due to the resource exhaustion caused by the DDoS attack, which in turn made the EKG signal unreliable for medical diagnosis and remote monitoring. In order to understand effect of TCP SYN attack on the EKG signal pattern, the attack was launched at different loads in a controlled lab environment. Finally, an Intrusion Prevention System was deployed in the network to mitigate the adverse effects of attack in the network in an attempt to recover a good EKG signal. Copyright © 2011 John Wiley & Sons, Ltd.

Effectiveness of Built-in Security Protection of Microsoft’s Windows Server 2003 against TCP SYN Based DDoS Attacks

Recent DDoS attacks against several web sites operated by SONY Playstation caused wide spread outage for several days, and loss of user account information. DDoS attacks by WikiLeaks supporters against VISA, MasterCard, and Paypal servers made headline news globally. These DDoS attack floods are known to crash, or reduce the performance of web based applications, and reduce the number of legitimate client connections/sec. TCP SYN flood is one of the common DDoS attack, and latest operating systems have some form of protection against this attack to prevent the attack in reducing the performance of web applications, and user connections. In this paper, we evaluated the performance of the TCP-SYN attack protection provided in Microsoft’s windows server 2003. It is found that the SYN attack protection provided by the server is effective in preventing attacks only at lower loads of SYN attack traffic, however this built-in protection is found to be not effective against high intensity of SYN attack traffic. Measurement results in this paper can help network operators understand the effectiveness of built-in protection mechanism that exists in millions of Windows server 2003 against one of the most popular DDoS attacks, namely the TCP SYN attack, and help enhance security of their network by additional means.

Mechanistic Aspects of Nucleophilic Substitution at Half-Sandwich Metal Complexes

The hydrolysis reactions of organometallic ruthenium(II) piano-stool complexes of the type [RuII(η6-cymene)(L)Cl]0/+ (1−5, where L = κ1- or κ2-1,1-bis(diphenylphosphino)methane, 1,1-bis(diphenylphosphino)methane oxide, κ1-mercaptobenzothiazole) have been studied using density functional theory at the B3LYP level. In addition to considering a syn attack in an associative fashion, where the nucleophile approaches from the same side as the leaving group, we have explored alternative paths such as an anti attack in an associative manner, where the nucleophile attacks from the opposite side of the leaving group. During the anti attack, an intermediate is formed and there is a coordination mode change of the arene ring from η6 to η2 along with its rotation. When the intermediate goes to the product, the arene ring slips back from η2 to η6 coordination. This coordinated movement of the arene ring makes the associative anti attack an accessible pathway for the substitution process. Our calculations predict very s...

Contrasteric Diels–Alder reactions of 5-methyl-5-phenylcyclopentadiene

Contrasteric Diels–Alder reaction of 5-phenylcyclopentadiene was predicted on the basis of the orbital mixing rule. The prediction was substantiated experimentally by the reactions of 5-methyl-5-phenylcyclopentadiene. The frontier molecular orbital of 5-phenylcyclopentadiene was predicted on the basis of the orbital mixing rule to deform to favor the Diels–Alder reaction in a syn contrasteric manner. The prediction was substantiated experimentally by the reactions of 5-methyl-5-phenylcyclopentadiene with dienophiles to afford the syn attack products, exclusively.

Analyzing multiple logs for forensic evidence

Information stored in logs of a computer system is of crucial importance to gather forensic evidence of investigated actions or attacks. Analysis of this information should be rigorous and credible, hence it lends itself to formal methods. We propose a model checking approach to the formalization of the forensic analysis of logs. A set of logs is modeled as a tree whose labels are events extracted from the logs. In order to provide a structure to these events, we express each event as a term of algebra. The signature of the algebra is carefully chosen to include all relevant information necessary to conduct the analysis. Properties of the model, attack scenarios, and event sequences are expressed as formulas of a logic having dynamic, linear, temporal, and modal characteristics. Moreover, we provide a tableau-based proof system for this logic upon which a model checking algorithm can be developed. We use our model in a case study to demonstrate how events leading to an SYN attack can be reconstructed from a number of system logs.

Active router approach to defeating denial-of-service attacks in networks

Denial-of-service attacks represent a major threat to modern organisations who are increasingly dependent on the integrity of their computer networks. A new approach to combating such threats introduces active routers into the network architecture. These active routers offer the combined benefits of intrusion detection, firewall functionality and data encryption and work collaboratively to provide a distributed defence mechanism. The paper provides a detailed description of the design and operation of the algorithms used by the active routers and demonstrates how this approach is able to defeat a SYN and SMURF attack. Other approaches to network design, such as the introduction of a firewall and intrusion detection systems, can be used to protect networks, however, weaknesses remain. It is proposed that the adoption of an active router approach to protecting networks overcomes many of these weaknesses and therefore offers enhanced protection.

Stereoselective Synthesis of Stannyl Enones via Palladium‐Catalyzed and Free Radical Hydrostannation of Alkynyl Ketones with Trineophyltin Hydride.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Stereoselective synthesis of stannyl enones via palladium-catalyzed and free radical hydrostannation of alkynyl ketones with trineophyltin hydride.

A study on the addition of trineophyltin hydride (1) to alkynones under free radical (AIBN and Et3B) and palladium-catalyzed [(PPh3)2PdCl2] conditions is reported. The results obtained indicate that the addition of 1 to eight ynones catalyzed by bis(triphenylphosphine)palladium(II) chloride led in all cases to addition products in very high yields (80-96%). These additions take place with excellent regio- and stereochemistry, leading to the alpha adducts as major products in seven out of the eight cases studied. Also the E adducts, resulting from a syn attack, were the only (seven cases) or the predominant (one case) products. The radical hydrostannations initiated by AIBN of ynones 2-5 with 1 led to addition products in good yields (60-88%); with the more hindered ketones 6 and 7-9 the yields obtained were lower. The radical additions initiated by triethylboron to ynones 2-6 follow a similar pattern but with lower yields; no addition products in the hydrostannation of ynones 7-9 were detected. The new acyl-substituted vinylstannanes, owing to their greater stability compared with that of their tributyl- and trimethylstannyl analogues, can be purified by column chromatography using neutral alumina (in all cases) or silica gel 60 (in most cases) as adsorbents. Full 1H, 13C, and 119Sn NMR data are given.

Origin of diastereofacial selectivity in tertiary 2-adamantyl cations.

The intrinsic factors governing the diastereofacial selectivity of 2-methyl-5-X-2-adamantyl cations (X = F (I(F)), Si(CH(3))(3) (I(Si))) toward a representative nucleophile, i.e., methanol, have been investigated in the gas phase at 750 Torr and in the 20-80 degrees C temperature range. The kinetic results indicate that CH(3)OH addition to I(F) proceeds through tight transition structures (TS(F)(syn) and TS(F)(anti)) characterized by advanced C-O bonding. The same interactions are much less pronounced in the comparatively loose transition structures involved in the CH(3)OH addition to I(Si) (TS(Si)(syn) and TS(Si)(anti)). The experimental evidence indicates that the activation barriers for the anti addition to I(F) and I(Si) are invariably lower than those for the syn attack. Large adverse entropic factors account for the preferred syn diastereoselectivity observed in the reaction with I(F). Entropy plays a minor role in the much looser transition structures involved in the reaction with I(Si), which instead exhibits a preferred anti diastereoselectivity. Comparison of the above gas-phase results with related theoretical and solution data suggests that the diastereofacial selectivity of I(F) and I(Si) measured in solution arises in part from the differential solvation of the two faces of the pyramidalized ions.

Stereoselectivity control in Diels–Alder reactions of 4-thiosubstituted 5-alkoxyfuranones: synthesis and reactivity of enantiopure 4-sulfinyl and sulfonyl 5-( l-menthyloxy)furan-2(5 H)-ones

The synthesis of enantiomerically pure ( S)-4-phenylsulfinyl- and 4-phenylsulfonyl-(5 S)-5-( l-menthyloxy)furan-2(5 H)-ones 5a and 6 and (5 R)-5-( l-menthyloxy)-4-phenylsulfonylfuran-2(5 H)-one 8 and the study of their reactions with cyclopentadiene are described. The sulfur substituents at C-4 modify (sulfone 8, anti/ syn=78/22) and invert (sulfoxide 5a and sulfone 6, anti/ syn≈27/73) the trend imposed by C-5 on the π-facial selectivity and the syn-adducts become the favoured ones. The endo or exo approach mode is favoured for anti ( endo/ exo ratio ranging between 26 and 5) or syn ( exo/ endo ratio ranging between 4.5 and 2.3) attack, respectively.