Most mathematical models representing infection spread in computer and wireless sensor networks (WSN) address only a specific kind of malware. However, researchers in the field of biosciences have modeled non-homogenous populations of contagions in a host. Motivated by this, we therefore propose the Vulnerable, Contagious due to virus, Contagious due to worm, Contagious due to trojan horse, Recovered with Inoculation (e-VCjRI) epidemic model, to describe the propagation dynamics of multiple breeds of malware in a WSN. Beside distinctive infectiousness, the e-VCjRI model possesses expressions for communication range and distribution density, which are renowned WSN attributes that constituted the actual threshold parameter (Ro) alongside differential infectivity as result of worm, virus and trojan horse. Put another way, the study illustrated that the true Ro is the summation of each malware group’s reproduction ratio. The Runge–Kutta order 4 and 5 numerical method was used to provide solutions for the system of differential equations, and afterward, the effects of the aforementioned WSN features were presented.