I recommend that you have good protection and utilities like: anti-virus, anti-spyware, and using safe browsing techniques such as a pop-up/ad blocker.
Bitdefender – (fee) – leading protection for your computer
Kasperksy – (fee) – excellent with detection rates.
Avast – (free) – has a large user base and security updates are often uploaded
Avira – (free) – somewhat slow with security updates but doesn’t require a lot of resources