Operating system malware can infect any operating system (OS), which means that it can infiltrate both Windows and Mac computers. If you download a malicious file, it could be disguised as something harmless, like an image file. Malware bytes and other types of malware detection software can find malicious files on your computer, but they aren't capable of preventing OS malware from infecting your computer in the first place. If you don't have a good antivirus program installed, it's a good idea to get one. Many antivirus programs also include malware detection, which makes them an essential part of computer security.