help me, guys!

about two days ago, my homepage was changed to new.searchopa.com, and since then I cannot do anything to replace it. I have tried to change homepage via Chrome settings, but surprisingly, I failed. I saw new.searchopa.com once again after I closed and reopened Chrome. What is going on and what is wrong with my browser? is new.searchopa.com virus? if not, why I cannot get rid of it?