The Security Mentor

Science fiction editor John Campbell once pointed out that chemical and biological weapons were inefficient as long as they depended on some kind of artificial delivery vehicle. The best weapons, he argued, would be those that the victims would go out of their way to expose themselves to. For example, not that anyone meant it that way, when Europeans were fighting natives for posession of the Americas, each side weakened the other using a toxic chemical (tobacco in one direction, alcohol in the other) which addicted the victims as well as crippling them.

Some researchers have suggested applying the same principle to computer viruses. Their theoretical design for a truly evil virus would offer people control over previously infected computers, in exchange for permission to install a little "viewer program" which of course would be the same virus that infected the other computers.

You might call it the "you can't cheat an honest man" virus.

Hasn't happened yet, but don't install software that promises you superpowers.