Is URinfosoft a reputable company ?

Since you have a backup, wiping the hard drive is unnecessary. Just restore from a backup that was made at a point before the scammers took control.

For more information, see the "What if I Called the Number?" section of: https://sites.google.com/site/appleclubfhs/support/advice-and-articles/browser-p opup-hijack-safari.

(Note that I am affiliated with that site, and some pages contain ads).