Multi-partite viruses

Multi-partite viruses share some of the characteristics of boot sector viruses and file viruses: They can infect .com files, .exe files, and the boot sector of the computer’s hard drive.

On a computer booted up with an infected diskette, the typical multi-partite virus will first make itself resident in memory then infect the boot sector of the hard drive. From there, the virus may infect a PC's entire environment. Not many forms of this virus class actually exist. However, they do account for a disproportionately large percentage of all infections.