Even innocent files, like games from popular websites, may have malware hidden in them. When you don't have an antivirus program installed, it is much easier to accidentally open a file or click on a link that unleashes malware. The threat inside these folders is then either scrubbed from the system or placed in a quarantine folder before being permanently deleted. The best antivirus software has real-time protections in place to stop malicious files from downloading or opening on your computer.