Multipartite viruses actually don't work like that. The difference is here: > researchers realized that a [biological] virus could be composed of two or more i

Multipartite viruses actually don't work like that. The difference is here: > researchers realized that a [biological] virus could be composed of two or more independent pieces, all of which were vital for infection multipartite computer viruses are monolithic; when they infect a boot sector, if there is not enough space, additional segments of the virus are stored in other parts of the disk (eg. masked as bad sectors), but it's still a single logical unit. It would certainly be an interesting idea for malware to break into independent pieces in separate logical locations (boot, files, etc.), but that's not how multipartite viruses traditionally work (or worked; I'm referring to DOS viruses).