Abstract: With the developing of network, botnet has become a major threat attack platform w Internet, The current network is a complex network consisting of the random network and the scale-free network. This paper, combining the features of scalcfree network, immunity and network traffic congestion, proposed a new botnet propagation model with two-factor on Scal}free network. This model considers carefully the real situation of the Internet, especially the Scale free network topology, immunity of the host removed from the susceptible network in advance and network traffic congestion. Simulation result shows that the botnet propagation model more exactly satisfies the practical propagation laws and infection characteristics of bot on Internet.

Key words: Scalcfree network, Botnet, Bot, Propagation model, Immunity, Network traffic congestion