Cannot change default Search engine/home

Hello, I downloaded a file a few days ago that ended up installing some Malware onto my iMac. I've gone through and cleaned it up as well as I could, I also ran Malwarebytes and it removed some things

The one thing that seems to be lingering is the default search engine and homepage in both Safari and Chrome. set to "Chumsearch". They appear in the preferences in both applications but are locked behind administrator. Im currently logged into the administrator account of my computer so I'm not sure what to do.

I'm assuming this difficulty is intended by the malware.

Any help would be appreciated