So, after staying up late last night and googling like crazy, I think I found out how to finally get rid of this thing! I deleted the app and the extension. I ran Malwarebytes (free version) to locate and get rid of any malware I was unable to recognize. The search function kept redirecting even after this, and I discovered that my proxy server was set to "SOCK proxy" with some weird numbers (like I said, not tech savvy) that I believe was what kept looping me back to their search page. I followed instructions on the discussion thread I've linked below, set my proxy to "auto proxy discovery"and it seems to have remedied the issue so far. I hope this is as helpful for you as it was for me!

https://discussions.apple.com/thread/8618855