Hoax

Definition
A hoax is

"[a]n email that warns users about imaginary malware (that is, that does not exist in reality). Hoaxes tend to follow a fairly standard pattern &mdash; they are generally written in highly technical and emotive language and often describe highly destructive, irreversible payloads (that may be physically impossible). Hoaxes also often appear to quote industry experts to claim legitimacy and they generally ask users to forward the message to as many people as possible."