Denial Of Service (dos)

A Denial Of Service(DOS) attack is an attack by an attacker to stop the needed ability from the aimed users. The attacker will use up the computational resources such as bandwidth, disk space and CPU time. In Distributed Denial of Service attack, hundreds or thousands of computer arrangement across the internet are coiled into zombies that are next utilized to attack one more arrangement or website that make the situation even inferior by dispatching memos to a specific server and make the ability unavailable for users. Public method to resolve the setback of DOS and DDOS is to manipulation constant appeal or flooding pending to the server. As packet flooding is discovered to be the public method utilized by attackers to craft Denial of Service. For controlling DOS attack, routers have to manipulation the flow of appeal pending to the server or , filter the appeal that are aimed to cause damage to the server. These methods rely on a key constructing block that can be joined alongside continuing request specific protection methods to craft safeguard, decentralised requests on structured overlays. These resolutions display efficiency in manipulating packet flooding but are inefficient after the attacker change his theories and buy extra strength opposing the network traffic laws and undeviating attack an application. As these resolutions are public and displays less effectiveness in request specific areas.

ABSTRACT--- Vehicular Ad-Hoc Networks (VANETs) isan indivisible component of I.T.S., where nodes are autonomous self-organizing and self- managing information in a distributed fashion. Its foundation is based on the co-ordination of vehicles and/or roadside units by which information is disseminated in network in organized way. In recent years, VANET has been taken more attention of automotive industries and researchers due to life saving factor. But always coin has two faces, when we know about its life saving factors at the same time security threats for VANET is also arises, so now VANET needs security to implement the ad hoc environment and serves users with commercial and safety applications. In this paper, we have done a survey of attack on network availability and its severity levels in VANET environment, which known as Denial of Service (DOS) attack, along with that different kind of hybrid Denial of Service attackis also present in it with their existing solutions.

Abstract: To construct and evaluate intrusion detection, system researchers are limited to only a few available public datasets unless they prepare their own. Although the most prevalent KDDCUP’99 dataset provides a comparative analysis among researchers, the community needs a new dataset which reflects new attack types in current high-speed networks. The aim of this study is to prepare a new alternative dataset for the community for detection of denial of service attacks and to conduct performance analysis of different data mining methods on this dataset. To develop the dataset, distributed DoS attacks have been generated that target a commercial website in a real network environment, which has a million of users from all over the world. In addition to this, a richer attack dataset has been produced in a laboratory environment with the help of Labris Networks. After capturing data, significant network features have been identified and processed and labeled with related attack types. Furthermore, the performances of different data mining techniques have been evaluated, including binary classification, multi-class classification, outlier detection, feature selection methods and hybrid approaches with our dataset by using the following algorithms: K-Means clustering, Naïve Bayes, Decision Tree, Multilayer Perceptron, LibSVM, Random Forest and Random Tree.

In [1], the authors, Pelechrinis, K. Iliofotou, M. and Krishnamurthy,S.V. from the university of California have surveyed the various types of denial of service attacks and the performance issues due to the DoS attack done to each network. They have provided several intrusion detection techniques in their survey and have mentioned that there must be system implementation to avoid real world adversaries. In all of the jamming techniques and the detection algorithms, through put is 0 which effectively reduces the performance of the network.

According to the WWW Security FAQ [5] on Distributed Denial of Service (DDoS) attacks: “A DDoS attack uses many computers to launch a coordinated DoS attack against one or more targets. Using client/server technology, the perpetrator is able to multiply the effectiveness of the DoS significantly by harnessing the resources of multiple unwitting accomplice computers, which serve as attack platforms”. The DDoS attack is the most advanced form of DoS attacks. It is distinguished from other attacks by its ability to deploy its weapons in a “distributed” way over the Internet and to aggregate these forces to create lethal traffic. DDoS attacks never try to break the victim’s system, thus making any traditional security defense mechanism inefficient. The main goal of a DDoS attack is to cause damage on a victim either for personal reasons, either for material gain, or for popularity. The main tool of DDoS is bulk flooding, where an attacker or attackers flood the victim with as many packets as they can in order to overwhelm the victim. The best way to demonstrate what a DDoS attack does to a web server is to think on what would happen if all the population of a city decided at the same moment to go and stand in the line of the local shop. These are all legitimate requests for service – all the people came to buy something, but there is no chance they would be able to get service, because they have a thousand other people standing in line before them. The zombie program can be planted on the infected hosts in a variety of ways, such as attachment to spam email, the latest cool flash movie, a crack to a game, or even the game itself. Communication from the zombie to its master can be hidden as well by using standard protocols such as HTTP, IRC, ICMP or even DNS [6].

Denial of Service (DOS) attacks are unlimited threat to internet sites and among the hardest security problems in today‟s Internet. The problem of DoS attacks has become well known, but it has been difficult to find out the Denial of Service in the Internet. Distributed Denial of Service (DDoS) attack is a large-scale, coordinated attack on an availability of services of a victim system or network resource, launched indirectly through many compromised computers on the Internet. Researchers have come up with more and more specific solutions to a DDoS problem [10].

Denial of Service (DoS) attack is the most popular and emerging threat for the past few years in the world of internet. A denial-of-service attack (DoS attack) denies the intended user to make use of the required resource by making it unavailable. The major goals of attackers are high profile web servers. With the increasing use of internet on every device, these attacks are spreading on a very large scale in numerous forms by many methods. Rather than relying on a single server, attackers could now take advantage of some hundred, thousand, even tens of thousands or more victim machines to launch the distributed version of the DoS attack. A distributed denial of service attack (DDoS attack) is a large-scale, coordinated attack on the availability of services of a victim system or network resource, launched indirectly through many compromised computers on the Internet [1]. The first well-publicized DDoS attack in the public domain was in February 2000. On February 7, Yahoo was the victim of a DDoS during which its Internet portal was inaccessible for three hours. Analysts estimated that during the three hours Yahoo was down, it suffered a loss of e-commerce and advertising revenue that amounted to about $500,000.

Abstract - A Wireless mesh network is a wireless communication between different nodes which are dynamically self-organized and self-configured. The nodes in the network automatically establishing an ad-hoc network and maintaining the mesh connectivity, nodes communicate with each other by forwarding data packets to other nodes in the network. Thus the nodes find a path to the destination node using routing protocols. However, due to security vulnerabilities of the routing protocols, wireless mesh networks are unprotected to attacks of the malicious nodes. One of these attacks is the Black Hole Attack and gray hole attack , against network integrity absorbing all data packets in the network and gray hole random drop the packets. Since the data packets do not reach the destination node on account of this attack, data loss will occur. There are lots of detection and defense mechanisms to eliminate the intruder that carry out the black hole attack. In this thesis, I have simulated the black hole attack in various wireless mesh network scenarios and have tried to find a response system in simulations. Denial of service attacks is one of the most common types of attack which is possible in WMNs. DoS attacks are most common in networks which connect to internet and since WMNs are mainly designed for fast and long distance internet access this type of attacks are common in the network. Wireless mesh networks consist of both mesh routers and mesh clients. I have confined my studies to mesh routers which are stationary. I have implement both Gray Hole attack and black hole attack in mesh routers and study the delivery ratio of the network with and without the presence of attack routers. By simulating the scenario with AODV protocol I have study the delivery ratio of packets and find out how it is affecting the network in the presence of an attack router.

A Denial of Service (DoS) attack does not steal or damage the server but blocks or prevents access to the server or website. Such DoS attacks target the network bandwidth or connectivity. Such attacks floods the network degrading the service provided to a genuine user who is not able to send or receive response from server. The attacker consumes most or all of the resources of the computer and operating system. A counterstrike is an action or process that prevents or mitigates the effects of the attack. In this paper we report on a project we have implemented based on the ideas of Yongdong Wu, Zhigang Zhao [13] where a software puzzle based counterstrike is used to deal with DoS attacks. There are basically three Types of DOS attacks: Smurf, UDP flood and SYN flood attacks. Despite the significant varieties of attacks there is a common objective amongst all types of DoS attacks. The attackers aim to exhaust the resources of the system that includes cpu cycles, memory, disk space and network bandwidth. The attackers generate too many requests which is feasible since they pay very little or nothing to request a service. Often their cost is only of sending the request on the network. However the attack can vary significantly in many aspects including the target and protocol layer of the network, distribution of attack sources, the strategy employed and the impact.

Security is one of the important concern of any communication network. Many attacks have been reported over the last several years. Most of them, however, target wired networks as compared to wireless. Now wireless networks have recently been gaining popularity as world is going towards wireless technology. Nowadays, with progress in wireless technology, the wireless network is becoming more affordable and easier to build. Many metropolitan areas deploy public WMANs for people to use freely. Moreover, the prevalence of WLANs as the basic edge access solution to the Internet is rapidly becoming the reality. However, wireless networks are vulnerable with an important security flaw; they are much easier to attack than any wired network. The shared and easy to access medium is undoubtedly the biggest advantage of wireless networks, while in particular, it makes it extremely easy for an attacker to launch an attack. Denial of Service Attack (DoS) has increased the importance of this protection as an accessibility view in the context of security, not just the resolution of confidentiality and integrity. Attackers use DoS in many different ways, including extortion threats, obfuscation, hacktivism and even friendly fire. C. Types of DoS Attacks in WSN

From the review of the above papers and different features, it can be concluded that many different techniques can be used to detect Distributed Denial of Service(DDoS) using different features.DDoS is a kind of DOS assault in which multiple compromised systems, which are frequently infected with a Trojan, are used to goal a single machine inflicting a Denial of service (DoS) attack.Hence, the detection has to be done in its earlier stages. There is a constant research happening in this field.right here, an strive is done to research and apprehend a number of the strategies used until now for the detection and classification of DDoS assault through the usage of some algorithms and the methods proposed within the reasearch papers.

Abstract: The Wireless Sensor Networks (WSNs) are emerging as one of the most reliable technologies for implementing ubiquitous computing ultimately leading to an all-pervasive paradigm of computing infrastructure that can be utilized for several interesting applications. Denial of Service (DoS) is an attack where a number of compromised systems attack a single target, thereby causing denial of service for users of the targeted system. The flood of incoming messages to the target system essentially forces it to shut down, thereby denying service to the system to legitimate users. DoS attacks disrupt the entire or a part of WSN network. Detection and avoidance of DoS attacks is necessary. For that we design message observation and common key authentication mechanisms by which cluster head (CH) as well as any other sensor nodes in network can able to identify the communicating node is an attacker node or not and isolate that attacker node. This approach is efficiently, detects and avoids Dos attack completely.

Abstract: Vehicular Adhoc Networks (VANETs) is the form of network which contains vehicles with high mobility as nodes. Since the nodes are moving, the vehicles entering and leaving the network is at very high pace making the VANETs self-organizing. Due to this, the dissemination of information to correct nodes and making the network secure from active as well as passive attackers is one of the vulnerable task in VANETs. There are number of attacks by which the network can be attacked but in this paper we have discussed Denial of Service (DoS) attack which attacks on the availability of the network. All the possible reasons of DoS attacks are reviewed and also all the possible solutions are defined in this paper.

Wireless Local Area Network (WLAN) have become very popular in almost all organizations and universities. WPA, WPA2, WEP, etc. are some of the examples of these Our WLAN’s are not protected from DoS attacks although it has many of these features. Interconnected systems, such as Webservers, database-servers, cloud- computing servers, etc. are under threats of network attackers.[1] Serious impact on computer system is caused by DoS attacks. Wireless solutions are quite important n various organizations, universities and many other places as there are no issues related to wired structured.[2] In wireless networks DoS attacks is of quite importance in present years. Demonstration show that Dos Attacks can be easily launched in MAC layer. The MAC addresses of wireless network devices is forged in most of the cases by the attackers to halt the operation of the wireless network. Such types of attack are easily available for attackers by many tools. Degradation of the network quality and loss of availability of the network within the organization is resulted by such attacks.[1] DDoS attack is a form of DoS attack in which attacker try to use the IP address of the legitimate user. It is an active category of attack among the two type of attack. The main aim of the attacker is to utilize all the resources so that user cannot use them. Large number of computers access is gained by them to set up attack armies (known as botnets) by exploiting their vulnerabilities. A large scale attack can be launched by these created army against the system. Several strategies could be used by the attacker to achieve this goal. The important and common among them is flooding the network with bogus requests. As multiple computer is used the attack is distributed to launch DoS attacks.[3] This paper reviews various denial of service attacks and there prevention/detection solutions. Paper shows how DoS attacks are created, some methods to prevent them and its types. We also identify the issues with existing countermeasure and provide future research directions.

Denial-Of-Service attack is one of the most common types of attack on online servers. DoS attacks, usually reduces the availability of resources to the clients. The Attackers severely impose large computation tasks by flooding it with huge rate of duplicate packets. Thus, the victim can be forced to be out of network services for few minutes to even several days. This causes serious problem to the victim. There are different types of DoS attacks are there and brief explanation is given in the fig-1[2]. In DoS attack detecting system deal with Network level, Application level and Data level attacks.

Denial of service (DoS) and Distributed Denial of Service (DDoS) attacks continue to threaten the reliability of networking systems. Previous approaches for protecting networks from DoS attacks are reactive in that they wait for an attack to be launched before taking appropriate measures to protect the network. This leaves the door open for other attacks that use more sophisticated methods to mask their traffic. A secure overlay services (SOS) architecture has been proposed to provide reliable communication between clients and a target under DoS attacks. The SOS architecture employs a set of overlay nodes arranged in three hierarchical layers that controls access to the target. We propose an architecture called secure overlay services (SOS) that proactively prevents denial of service (DoS) attacks, which works toward supporting emergency services, or similar types of communication. The architecture uses a combination of secure overlay tunneling, routing via consistent hashing, and filtering. We reduce the probability of successful attacks by: 1) performing intensive filtering near protected network edges, pushing the attack point into the core of the network, where high-speed routers can handle the volume of attack traffic and 2) introducing randomness and anonymity into the forwarding architecture, making it difficult for an attacker to target nodes along the path to a specific SOS- protected destination. Using simple analytical models, we evaluate the likelihood that an attacker can successfully launch a DoS attack against an SOS protected network. Our analysis demonstrates that such an architecture reduces the likelihood of a successful attack to minuscule levels.

is due to its on-demand, self-service, and pay-by-use nature. According to this paradigm, the effects of Denial of Service (DoS) attacks involve not only the quality of the delivered service, but also the service maintenance costs in terms of resource consumption. Specifically, the longer the detection delay is, the higher the costs to be incurred. Therefore, a particular attention has to be paid for stealthy DoS attacks. They aim at minimizing their visibility, and at the same time, they can be as harmful as the brute-force attacks. They are sophisticated attacks tailored to leverage the worst-case performance of the target system through specific periodic, pulsing, and low- rate traffic patterns. In this paper, we propose a strategy to orchestrate stealthy attack patterns, which exhibit a slowly-increasing-intensity trend designed to inflict the maximum financial cost to the cloud customer, while respecting the job size and the service arrival rate imposed by the detection mechanisms. We describe both how to apply the proposed strategy, and its effects on the target system deployed in the cloud.

You can also check your log files for suspicious activity. Here is what a normal log file looks like: IIS (and other web servers) allow you to configure the log files in many ways, so your log files may look different, but will contain the information I discuss below. The important fields to look at are c-ip (the ip address of the person or program that is visiting your site), cs-uri-stem (which tells you which page they are visiting, and cs (User-Agent), which tells you which program is being used to visit your website (e.g. IE, Firefox, Google Chrome, etc.) Note that in the table above, we see several different IP addresses for our clients (89.248.174.2, 217.196.17.20, 66.249.67.153, etc.), different WebPages (/Financial/Default.aspx, /financial/StyleSheet.css, etc.) and different user agents (IE 8 and a Google "bot" ) Here is what the log file might look like during a Denial of Service attack: Note that we are seeing the same IP address (69.163.239.247) again and again (for hundreds of lines), that this bot or user is accessing the same web page again and again (/ is the root page of my website), and that the program accessing our website is called Apache Bench. Each time a user visits one of your pages, you should expect to see about 1-10 lines in the log files for that user's visit, and you should see the user's web browser downloading an html page (on one line), and any art or links embedded in that page downloaded (each also on its own line). What you don't expect to see is the same item downloaded again and again and again by the same IP addresses hundreds of times. This is what a Denial of Service (DoS) looks like. Also note that the suspicious lines also show the use of Apache Bench. From apache.org, "Apache Bench is a tool for benchmarking

Denial of service (Dos) problem has great impact on all devices in automation system. A lot of techniques have been developed that can protect systems from Dos attack. This paper presents some proposal solutions to solve this problem in order to decrease the risk factor by Using Trusted Authentication Device, Counter, and connecting the network with two routers. The first router is the basic and the other one is reserve. Then, dividing the devices into normal and vip devices, connecting vip devices with two networks, Trust Point (TP) to prevent attackers from access to AS and the optimal solution mixing between the previous ones .

1a. DENIAL-OF-SERVICE (DOS) ATTACK: In a denial-of-service (DoS) attack, an attacker attempts to prevent legitimate users from accessing any services and information. By attacking your computer and its network connection or sites you are making use of, an attacker may able to prevent you from accessing any of your email, websites, online accounts (banking, etc.), or other services that rely on the affected computer.