Browser Malware
If your internet page is being blocked or redirected you need to download, install then run Malwarebytes this application is available on the College Managed Software Centre or you can download it from the site: https://www.malwarebytes.com/mac-download/
Once you have installed this software run a system scan with all the other applications closed and wait until the scan is finished then follow the instructions.
There is also a MalwareBytes App for Chrome this is also advisable to have installed. Link: https://chrome.google.com/webstore/detail/malwarebytes-browser-exte/ihcjicgdanjaechkgeegckofjjedodee
Once this is done if it's still a problem please reply and at a time will be allocated for it to be investigated