关键词: 应用层拒绝服务攻击, 浏览行为, 蚁群聚类算法, 异常检测

Abstract: A novel method using ant clustering to detect application layer Distributed Denial of Service（DDoS） attacks is presented.According to the difference between normal users’ browsing patterns and abnormal ones，user sessions are extracted from the web logs of normal users and similarities between different sessions are calculated，an improved ant clustering algorithm is employed to generate an adaptive detecting model.This model can be used to detect whether the undetermined sessions are DDoS attacks or not.The experiment results show that this method can detect attacks effectively and has a good performance in adaptability.

Key words: application layer denial of service attack, browsing behavior, ant clustering algorithm, abnormity detection