search.searchisemail.com - Browser hijacker

I've just run a full scan in Norton 360 which did find a couple of W97 trojan issues and reported them fixed. However on restart this "searchisemail" is still hijacking my search function in Firefox (v 52.1.2 ) despite Google being selected as default Search browser in the Options menu.

Online comments describe it as a virus or Trojan, which I agree with.

Is there a fix coming in 360??