Towards the understanding of the mixed behavior of electronic viruses and countermeasures

The compartment modeling of computer viruses is recognized as an effective approach to the understanding of their propagation and containment. The recently proposed SICS model takes into account the dissemination of countermeasures as well as the propagation of viruses; as thus, it offers a new approach to the evaluation of effectiveness of countermeasure strategies. However, the linear assumption of the infection rate in the SICS model fits well with the real situation only when the number of infected nodes is very small. To better understand the virus-countermeasure mixed behavior, in this paper the SICS model is modified by introducing a nonlinear infection rate. Depending on the parameter values, the new model may have one or two equilibria. Furthermore, the global stabilities of the two equilibria, if any, are determined completely. On this basis, some policies to contain the viral prevalence are suggested.