This paper studies the fractional order model for computer virus in SIRA model, with the antidotal class incorporated. Firstly, the basic reproduction number, R0, which determines the threshold of the spread of the virus is calculated. The stability of the equilibria was also investigated and studied. To illustrate our theoretical analysis, some numerical simulations were carried out, using Adams-type predictor-corrector method, to show the behavior of the solutions of the proposed fractional order system. The results provide a theoretical basis to control the spread of computer virus. The simulations, also, showed that the fractional model gives a better result than the integer models.