Black hat
（重定向自Blackhat）
A black hat hacker is a hacker who "violates computer security for little reason beyond maliciousness or for personal gain."
The term was coined by Richard Stallman, to contrast the maliciousness of a criminal hacker versus the spirit of playfulness and exploration of hacker culture, or the ethos of the white hat hacker who performs hackerly duties to identify places to repair. It is a reference to the black and white hat symbolism in film.