To the best of my knowlege, there is no such thing as a virus attack on a router. There is no operating system in a router to attack. You need a computer to access a router, so it would not make sense to disable a router in the first place, as there are no benefit in it for the virus creator, who wants the virus to spread, and a dead router cannot help in that.
There can be attacks on your router by someone that wants to access it, to steal your bandwidth, or to access your computer, that can happen.
The only "antivirus" for this kind of attacks is to make sure you use a very strong username and password to access your router and your internet account, and not the router default passwords.