An Algorithm for Moderating DoS Attack in Web Based Application

The denial of service attack is the most powerful damaging attacks used by hackers to harm a business or organization. This attack is one of most dangerous cyber-attacks. It causes service outages and the loss of millions, depending on the time of attack. In past few years, the use of the attack has enlarged due to the accessibility of free tools. This tool can be blocked simply by having a good firewall, but an extensive and clever DoS attack can avoid most of the restrictions. A Denial of Service attacks against Web sites occur when a hacker attempts to make the Web server, or servers, unavailable for legitimate users and finally, to take the service slowing them down. This is attained by flooding the server's request queue with fake requests. After this, server will not be capable to handle the requests of genuine users. For some time, it was thought that these types of attacks were generally used against large companies, government sites, and activist sites as a form of protest to interrupt their Web presence. In general, there are two forms of the DoS attack. The first form is on that can crash a server. The second form of DoS attack only floods a service. Online Vulnerability Scanner is a tool which is capable to detect DoS Attack in Web application and compare its performance. We proposed an aegis algorithm which can be used to moderate DoS attack in Web application Vulnerability.