We study a modified model for propagation of computer virus with effective antidote in the network. Dynamical behavior of themodel is investigated by analyzing the stability of two disease-free equilibria and one endemic equilibrium. For positive antidotal population, one disease-free equilibrium is globally asymptotically stable. We found certain conditions for decreasing of propagation of computer virus in the network. A general formula for iterative solutions of the model is defined by the homotopy perturbation method that makes an advantage in using mathematical packages to solve nonlinear problems.