Does MacBook need virus cleaner

Hi everybody,

I have been receiving pop-ups telling that my MacBook is infected with virus and need cleaning. One of the pop-up ad was apparently from Apple Care centre but in the address window it indicated as "not secure". I just wanted to know if the MacBook could be infected and what is the secure way to clean it? A year back I did not ever receive any such ads. I am using MacBook Pro 13" (Late 2011).

Thanks for your advice and time.