Botnets continue to constitute a major security threat to users of the internet. We examine a novel security game between a bot master and the legitimate users of the compromised network. The more a bot master utilizes his botnet, the more likely it is he will be detected by the legitimate users of the network. Thus he must balance stealth and aggression in his strategic utilization of the botnet. The legitimate users of the network must decide how vigilant they will be in trying to detect the presence of the botnet infection. We establish the existence of a unique, pure, symmetric Nash equilibrium in a game with homogeneous agents. Network effects are numerically explored in relation to the infectivity of the network.