  In this paper, the non-linear modified epidemiological model of computer
viruses is illustrated. For this aim, two semi-analytical methods, the
differential transform method (DTM) and the Laplace-Adomian decomposition
method (LADM) are applied. The numerical results are estimated for different
values of iterations and compared to the results of the LADM and the homotopy
analysis transform method (HATM). Also, graphs of residual errors and phase
portraits of approximate solutions for $n=5,10,15$ are demonstrated. The
numerical approximations show the performance of the LADM in comparison to the
LADM and the HATM.
