[OMJenke]

I'm trying to fix my little brothers Mac and was wondering if there are any malware removal tools like they have for PC?

He plays a lot of these random ass games that he downloads off of god knows where and he catches these yahoo search helpers and macboosters and all this random shit.

[EliteTM]

I personally would just format and reinstall. If you have a few extra USBs or an external hard drive laying around, put all your personal files on there and then wipe the Mac following this guide.