Multi-Partite Viruses

From the virus writers point of view there are advantages to both boot sector and file viruses. For example a boot sector virus can spread via a data diskette and there are a lot of them floating about. However, it cannot be transmitted over the Internet. Nor can you get a boot sector virus from a bulletin board, or a CD or a network. You can however get a file virus from all of those places.

It didn't take long for some virus writer to workout that it was possible to write a virus that infects both the boot/partition sector and files. The theory is the virus will infect the boot/partition sector of your hard disk and then infect the files on your hard disk. It will also attempt to infect the boot sector of any diskette you insert into the PC.

However, it has proved more difficult to write a boot/partition sector virus which also infects files than a file virus that infects the boot/partition sector. The result is that with most of these viruses, if you get the boot sector version you do not get the file version.

A sub-set of this type of virus is the Dropper. This is a file virus that just puts a boot/partition sector virus on to hard disk.