Chum search is set as my homepage and I cannot change it.

Credit: thomas_r

If you've already scanned with Malwarebytes (I'm unsure if that's what you're talking about or not) and it found nothing, you may have been bitten by a Safari bug.

There appears to be a bug in recent versions of the system that can result in difficulty changing Safari's home page setting. In cases where adware has changed this setting, that can leave you stuck with an inappropriate home page, even after all the adware has been removed, with seemingly no way to fix it.

The following procedure appears to solve the problem:

* In Safari, choose Preferences from the Safari menu.

* In the window that opens, click the General icon (if necessary)

* Enter your desired home page in the "Homepage" field, but DO NOT press return!

* At the top of the window, click any of the other icons (eg, Tabs, AutoFill, etc).

* You may see a prompt asking for confirmation for changing the home page. If so, confirm.

* Switch back to the General page and check to make sure the home page has been changed.

https://discussions.apple.com/thread/8018092

Home Page Locked - https://discussions.apple.com/thread/8058186

Force Quit Safari ( command + option + esc keys).Then restart Safari holding the Shift key. If you still have problems Empty Caches (Safari menu > Preferences > Privacy > Remove all website data. (This will also remove history if you do not want to remove History open Safari Preferences > Advanced and check mark “Show Develop Menu” then choose “Empty Caches” from Develop Menu ).

Then go to Safari Preferences > Extensions and check there. If there is an extension delete it.

After taking these steps restart and then you should be able to reset the Homepage?

Remove Chumsearch.com from Mac OS and Windows (Guide)