The Potentially Harmful Files category includes various formats of potentially malicious and harmful file types for your computer. The files may be regular files or software that is sent to you (like the familiar .RAR and .EXE files) and can be a potential threat to the safety of your computer. The file types include known virus extensions as well as Trojan horses, spyware, adware, and other threats. You may find them hiding in email attachments or sent to you in some other way. Common potentially harmful file extensions are .EXE, .DRV, and .JS.