A new dynamical model of computer virus

Based on the assumptions of (1) a computer possesses infectivity immediately when it is infected, and (2) latent computers have a lower cure rate than behaving computers, a computer virus propagation model with graded cure rates is established. The dynamical behaviors of this model are investigated qualitatively. First, the basic reproduction number, R 0, for this model is determined. Second, the dynamical properties of this model are shown to be determined by R 0. Specifically, virus-free equilibrium is globally asymptotically stable if R 0 ≤ 1, whereas the local asymptotical stability of the viral equilibrium is guaranteed if R 0 > 1, followed by a conjecture on its global stability. Then the sensitivity analysis of R 0 to five system parameters is conducted, and the dependence of R 0 on the remaining system parameters is investigated. On this basis, a collection of policies is recommended for controlling viruses spreading across the Internet effectively.