malfunction vs fail

malfunction is a noun but fail is not a noun.

Word	Noun	Adjective	Verb	Adverb
malfunction	Yes	No	Yes	No
fail	No	No	Yes	No

As verbs, fail is a hypernym of malfunction; that is, fail is a word with a broader meaning than malfunction:

Other hypernyms of malfunction include break, break down, conk out, die, give out, give way, go, go bad.

malfunction (noun)	fail (noun)
a failure to function normally

malfunction (verb)	fail (verb)
fail to function or function improperly	stop operating or functioning
	deteriorate
	prove insufficient
	disappoint, prove undependable to; abandon, forsake
	become bankrupt or insolvent; fail financially and close
	be unsuccessful
	fail to get a passing grade
	fail to do something; leave something undone
	judge unacceptable
	be unable
	fall short in what is expected