Detecting HTTP-based application layer DoS attacks on web servers in the presence of sampling

摘要

A recent escalation of application layer Denial of Service (DoS) attacks on the Internet has quickly shifted the interest of the research community traditionally focused on network-based DoS attacks. A number of studies came forward showing the potency of attacks, introducing new varieties and discussing potential detection strategies. The underlying problem that triggered all this research is the stealthiness of application layer DoS attacks. Since they usually do not manifest themselves at the network level, these types of attacks commonly avoid traditional network-layer based detection mechanisms.