firebug vs malefactor

firebug and malefactor both are nouns.

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

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

firebug: a criminal who illegally sets fire to property
malefactor: someone who has committed a crime or has been legally convicted of a crime

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

firebug (noun)	malefactor (noun)
a true bug: brightly colored bug that can exude a stain	someone who has committed a crime or has been legally convicted of a crime
a criminal who illegally sets fire to property