Popups
1. Click menu in the menu bar, hold the shift key on the keyboard down
and choose “Force Quit Safari” from the dropdown.
Safari will quit.
Launch Safari holding the shift key down.
For more info:
Section: Pop-ups and ads in Safari: https://support.apple.com/en-us/HT203987
2. Remove Adware
Run the latest release of Malwarebytes for Mac to remove malware/adware, if installed on your Mac.
For instructions: Install Malwarebytes for Mac v4 Uninstall Malwarebytes for Mac
Click the “Scan Now” button. Once done, quit Malwarebytes for Mac.
Restart the computer and relaunch Safari holding the shift key down.
Repeat the scan couple of times.
Malwarebytes for Mac app and EtreCheck are developed by a members of Apple Support Communities
and are very much trusted.
Additional steps to take if necessary (1)
1. Remove unknown extensions: Safari > Preferences > Extensions
https://support.apple.com/guide/safari/use-safari-extensions-sfri32508/mac
2. Reset search engine: https://support.apple.com/guide/safari/customize-your-search-ibrwe75c2a3c/mac
3. Reset Homepage. https://support.apple.com/guide/safari/set-your-homepage-ibrw1020/mac
4. Restart your Mac. Relaunch Safari holding the Shift key down.
3. If this doesn’t help:
Download EtreCheck: https://etrecheck.com/ run it and post the report here.
Click “Click to download” button,
Open Downloads folder, click on it to open, and then select ”Open”.
“Choose a problem” from the popup menu box, and then “Start EtreCheck” in the dialog.
Click “Share Report” button in the toolbar, select “Copy report” .
Paste the report when you reply.