Malwarebytes is safe to use. The software is an on-demand virus scanner that can be used to run a scan on a computer if the owner suspects that a virus has infected the operating system.
Malwarebytes is a type of software known as a second opinion scanner. These programs provide an additional layer of defense for a computer in addition to existing antivirus software already installed on the computer. Many virus programmers code their malware to evade detection by most major antivirus publishers, so a second piece of software may provide an additional layer of protection. Malwarebytes is available in free and paid versions.