This type of virus is usually contained on a floppy and can only infect the PC when the machine is booted with the floppy inserted. These are some the earliest types of viruses since older machines used floppies to a great extent. A software error. Unlike a virus, a bug represents a mistake, not a deliberate attempt to cause computer problems. A hoax is just that.
Hoaxes tend to spread through chain e-mails.
A hoax will claim everything from the existence of a new and destructive virus, to the desperate plea for help for some poor fellow. Hoaxes which have been around for a while move into the the category of Urban Legends. These viruses take advantage of the integration of email and Microsoft Word. Trojan Horses often set up Backdoors, or secret entry points, into a program or machine and can conceivably allow outside access. VBS scripts are small programs.