Virus are scripts written to cause trouble to a specific system. It's specific like enzyme.
A virus written for a computer will not affect a phone. A virus written for Windows will not affect a Mac(normally)

but of course if got mobile phone virus, then will affect but mobile phone virus are still not that common at the moment

minor minor upgrades equals to major upgrades

You use hard casing is it?
My brother's PSP also super scratchy cause use hard casing. Dust and sand I cause the problem.