attacker vs offender

attacker and offender both are nouns.

Word	Noun	Adjective	Verb	Adverb
attacker	Yes	No	No	No
offender	Yes	No	No	No

As nouns, offender is a hypernym of attacker; that is, offender is a word with a broader meaning than attacker:

Other hypernyms of attacker include wrongdoer.

attacker (noun)	offender (noun)
someone who attacks	a person who transgresses moral or civil law