Tsunami: A parasitic, indestructible botnet on Kad

While current botnets rely on a central server or bootstrap nodes for their operations, in this paper we identify and investigate a new type of botnet, called Tsunami, in which no such bottleneck nodes exist. In particular, we study how a Tsunami botnet can build a parasitic relationship with a widely deployed P2P system, Kad, to successfully issue commands to its bots, launch various attacks, including distributed denial of service (DDoS) and spam, at ease, as well as receive responses from the bots. Our evaluation shows that in a Kad network with four million nodes, even with only 6% nodes being Tsunami bots, Tsunami can reach 75% of its bots in less than 4 minutes and receive responses from 99% of bots. We further propose how we may defend against Tsunami and evaluate the defense solution.