Remove Yahoo Search hack from Safari
I recently downloaded and installed OS Mojave and ever since then my searches in Safari are redirected from my default search engine, Google, to Yahoo. I see this is a common hijack that can get installed when downloading new third party software but I only downloaded the Mac OS.
What can I do, short of reinstalling the system, to remove this hack? I've tried using Malwarebytes and deleting an apple.com plist related to Safari (don't recall exactly which one) and zapped the pram on restart. When I first test this problem out, I get a Google search, on second and subsequent tries, it goes back to Yahoo.
Any suggestions would be greatly appreciated, the easier the better of course. No extensions are installed.
MacBook Pro 15″, OS X 10.11