  The new generation of botnets leverages Artificial Intelligent (AI)
techniques to conceal the identity of botmasters and the attack intention to
avoid detection. Unfortunately, there has not been an existing assessment tool
capable of evaluating the effectiveness of existing defense strategies against
this kind of AI-based botnet attack. In this paper, we propose a sequential
game theory model that is capable to analyse the details of the potential
strategies botnet attackers and defenders could use to reach Nash Equilibrium
(NE). The utility function is computed under the assumption when the attacker
launches the maximum number of DDoS attacks with the minimum attack cost while
the defender utilises the maximum number of defense strategies with the minimum
defense cost. We conduct a numerical analysis based on a various number of
defense strategies involved on different (simulated) cloud-band sizes in
relation to different attack success rate values. Our experimental results
confirm that the success of defense highly depends on the number of defense
strategies used according to careful evaluation of attack rates.
