The English Wikipedia has an article on anti-fans in Korean pop. What's the word Koreans use for an "anti-fan"?
informal form in daily conversations: -까
e.g) 소시까 (anti-SNSD)
natives much more frequently say '-까' than '-안티' in their conversations, of course '-까' is not formal
krdic.naver.com/detail.nhn?docid=6081400 / 까다 (verbal, ko-ko) 5. (속되게) 남의 결함을 들추어 비난하다.
and: endic.naver.com/… / 까다 (verbal, ko-en) 5. (비난하다, 욕하다) knock, run down, (Brit, inf) slate
so.. here -까 is derived from '까다', which means . Of course it is NOT recommended to use this word in formal conversations.