DDoS attacks and anomaly detection(DDoS攻击与异常检测).docx

DDoS attacks and anomaly detectionJulianneAbstract: This paper presents the special meaning of DDoS Attack and some anomaly detection method to deal with it. And compared different methods with each other．Finally，discussed the existing problems and the future direction in this field.Keywords: DDoS attack, attack detection, network.IntroductionDistributed Denial of Service (DDoS) attack refers to the use of c/s technology, combining a multitude of computers as an attack platform to launch a DDoS attack for one or more targets, thus doubling the power of denial of service attacks. Usually, an attacker uses a steal account to install the DDoS master control program on a computer which communicate with a large number of agents in a set time. And the proxy program has been installed on an ocean of computers of an internet, attacking as soon as the proxy receives instructions.BackgroundDDoS Attack traces back to 1996 first, began to appear frequently in 2002, and become take shape in 2003. It gradually evolved into three common forms of attack include the following:2.1 Traffic attacks: Traffic flooding attacks send a huge volume of TCP, UDP and ICPM packets to the target. Legitimate requests get lost and these attacks may be accompanied by malware exploitation.2.2 Bandwidth attacks: This DDos attack overloads the target with massive amounts of junk data. This results in a loss of network bandwidth and equipment resources and can lead to a complete denial of service.2.3 Application attacks: Application-layer data messages can deplete resources in the application layer, leaving the targets system services unavailable.Security issues and solutionsDDoS attack as a typical attack mean of the network security has never stopped from the birth of it. There are some representative events as follows:3.1.1 Estonia suffered three rounds of DDoS attacks within three weekson May of 2007.The presidential palace ,the parliament ,almost all the government departments, the major political