My site is compromised

Hi, I’m new on WordPress and guess what, my site is hacked. I’ve tried everything but there’s no results. Now, there’s one option remain. I have to switch my theme and now i’m asking you can if I switch my theme (news maxx) to some another and then pass files to new theme, will with the files pass also a hack file?
Or hack remain on theme. Can I hire someone and where if I can, to clean my site, or i have to change theme.
Thank you.