ask.com

Try selecting the ask.com extension, clicking the uninstall button on the right. Then on the keyboard, press Option + Command + E. This will clear out your cache. Then close the browser and re-open.

You may have adware/malware installed. Download this program which was written by Thomas Reed, a long time poster. The program will search for malware/adware The program will do the work for you which makes it easy. It may be necessary to run more than one scan. After scanning a couple of times, restart the computer and test.

 Malwarebytes Anti-Malware for Mac      10.10 and later

 Malwarebytes uninstall

Go to Safari Preferences > Extensions tab: --you can disable uninstall any extensions you don't want.