The best advice to avoid viruses;

Avoid free movie, games and file sharing websites. If an online service offers something for free, they're either intentionally attempting to deceive you, or you are the product. So why do Antivirus companies offer free software? While it may be part altruism, it's also required to keep their paid business Antivirus products functional by ensuring the general population keep the virus rate down.

Avoid opening email attachments and be critical of email content: There are very few legitimate services that still use email attachments. Banks and Australia Post never attach files. They also never use links in their email. When you are presented with a web link in an email hover your mouse over it and see if it goes where it should. Often scammers try to disguise links to look legitimate. Best practice is to avoid the link completely and make your own way to the web site.

Avoid adding Browser extensions or frivolous apps: such as changing your mouse cursor, sounds or a custom browser home screen. These are often culprits in distributing malicious code which either hijacks your computer or sends your personal information and online data to unknown people.