Multipartite virus

A multipartite virus is a computer virus that’s able to attack both the boot sector and executable files of an infected computer.

How do I know if have a multipartite virus?

• Drive controllers will no longer be present in Device Manager
• You receive frequent notifications that virtual memory is low
• Applications and files sizes continually change
• Hard drive reformats itself
• Word processing document extensions modified from DOC to DOT
• Programs may or may not execute, and will experience much longer loading times

Source: handwiki