Antivirus scans and helps remove malware files that enter a computer, tablet or smartphone. Norton Anti-Virus technology uses machine learning to determine if a file is good or bad, and can do so even if it’s the first time seeing that file. Norton protection also uses “emulation” (running each file in a lightweight virtual machine) to cause online threats to reveal themselves. This happens in milliseconds as you double-click on files on your desktop. File signature data is now stored in the cloud, and Norton protection has undergone hundreds of optimizations on the antivirus engine to minimize impacting the user experience.