  This paper addressed the issue of estimating the damage caused by a computer
virus. First, an individual-level delayed SIR model capturing the spreading
process of a digital virus is derived. Second, the damage inflicted by the
virus is modeled as the sum of the economic losses and the cost for developing
the antivirus. Next, the impact of different factors, including the delay and
the network structure, on the damage is explored by means of computer
simulations. Thereby some measures of reducing the damage of a virus are
recommended. To our knowledge, this is the first time the antivirus-developing
cost is taken into account when estimating the damage of a virus.
