abnormal add on opening safari

Go step by step and test.

1. Click  in the menu bar and choose “Force Quit”.

In the window that opens up, select “Safari” and click “Force Quit.

Relaunch Safari holding the shift key down.

2. Use Malwarebytes Anti-Malware for Mac to remove adware, if any.

https://www.malwarebytes.org/antimalware/mac/

Download, install , open, and run it by clicking “Scan for Adware” button to remove adware.

Once done, quit Malwarebytes Anti-Malware for Mac.

3. Disable Extensions and test.

Safari > Preferences > Extensions

Select and disable all extensions and test.

Enable Extensions one by one and test.

To uninstall any extension, select it and click the “Uninstall” button.

4. Safari > Preferences > Search > Search engine:

Select your preferred search engine.

Please read If Safari is slow, stops responding, quits unexpectedly, or has other issues - Apple Support.

The following may also be relevant: Safari for Mac: If you need to remove a Safari plug-in.