malefactor (n.)

mid-15c., malefactour, "a law-breaker, a criminal, a felon," from Latin malefactor, agent noun from past participle stem of malefacere "to do evil," from male "badly" (see mal-) + facere "to do, make" (from PIE root *dhe- "to set, put"). From late 15c. in the now-obsolete sense of "one who does evil or injury to another" (the opposite of benefactor).