Did you run a scan with Malwarebytes? Did it find any malicious items?
On which browsers are you experiencing this issue - Safari, Chrome, or Firefox? What extensions are currently installed on the browser? What are the browser settings for the homepage and search engine?
Also can you please check if there's an AdminPrefs file on the device. If it's there, you should remove it.
Go to System Preferences.
The list will include an item “AdminPrefs“. Select this and click the remove “–” button in the lower left corner.
I followed the directions to get to the AdminPrefs, yet did not see a "-" to click on. Weknow.ac is in my Adminprefs and has highjacked my brewer. Please help me get rid of it. I have run Malwarebytes, yet it did not detect anything.