mafioso vs malefactor

mafioso and malefactor both are nouns.

Word	Noun	Adjective	Verb	Adverb
mafioso	Yes	No	No	No
malefactor	Yes	No	No	No

As nouns, malefactor is a hypernym of mafioso; that is, malefactor is a word with a broader meaning than mafioso:

mafioso: a member of the Mafia crime syndicate in the United States
malefactor: someone who has committed a crime or has been legally convicted of a crime

Other hypernyms of mafioso include criminal, crook, felon, outlaw.

mafioso (noun)	malefactor (noun)
a member of the Mafia crime syndicate in the United States	someone who has committed a crime or has been legally convicted of a crime
a member of the Sicilian Mafia