I would think that viruses are the work of Satan and his demon minions considering how many of them attempt to sway the infected with lewd lies, but it might also be God's punishment, too! Computer viruses are often caught while... (please forgive me for even mentioning it, Pastors) people attempt to sate their perverted lust.
According to James 1:14-15, their lustful sins gave way to the death of their computer.