A virus is a type of malware, but not all malware are viruses. Malwarebytes can detect viruses, but it cant clean them if the virus is attached to the original file. Viruses can replace other files with a copy of themselves or attach their code to existing executables. The most important thing however is to be adequately protected against and to be aware of the dangers. The main routine has the same payload, but the files differ in shape and size. This is a method used to avoid detection by anti-viruses that are based on file detection.”]
Source: https://blog.malwarebytes.com/cybercrime/2015/05/malware-vs-virus-what-is-the-difference/