Welcome to the Security Center forum,
It sounds like you may have been infected with a browser hijacker. A potentially unwanted program or browser attachment may have compromised your internet browser settings.
There are 2 things I would like you to do:
1. Run another scan with Malwarebytes
2. Run a second scan with HitmanPro
Also see:
- How to change your Google Chrome homepage
- How to change your Google Chrome search engine
- How to remove extensions from Chrome
- How to change your Mozilla Firefox homepage
- How to change your Mozilla Firefox search engine
- How to remove add-ons from Firefox
- How to change your Microsoft Internet Explorer homepage
- How to change your Microsoft Internet Explorer search engine
- How to remove add-ons from Internet Explorer
Let me know how it goes. Good luck!