Anatomy of botnet on application layer: Mechanism and mitigation

Botnet-based DDOs attacks progressively using regular-looking application layer requests to exhaust disk capacity as well as server CPU. In the last decade, a number of defense and mitigation mechanisms have emerged to resist botnet. It is important to organise and compare these mechanisms to better understand the problem as well as solutions. Effective defense against botnet-based attacks at OSI layers has been deployed economically. The efficacious reactive approaches for application security are insufficient and enhanced proactive approaches are required. Current studies are curbed in span and do not usually include mitigation techniques to combat botnet threat. Our approach is to establish a fundamental perceptive of different botnet mechanisms employed by each botnet category and the proactive methods to mitigate botnet threat. This paper compares various existing categories of botnet in terms of their timeline, strength and behaviours during each lifecycle phase along with various network and application level mitigation techniques.