Nibu is just one of the variants in a “family of virusses”. W32.Backdoor.EZbot W32.Backdoor.Lid W32.Backdoor.Nibu W32.Backdoor.Nibu.B W32.Backdoor.Rado W32.Backdoor.Socakaps

As far as I know Avast is perfectly capable of handling all virusses.

And you must not confuse a virus with a trojan or spy-/adware.