Several sites hacked - can I use newer version of PHP now?
I only use Design Extender for the CMS. I have CMS on several sites. Some with and some w/o were hacked yesterday. All in the same hosting account. I am running PHP 5.6 on server. I remember when I first installed CMS years ago I was not able to use latest PHP version. Can I upgrade now to eliminate vulnerabilities or is there something I need to do with my code to prevent this from happening again? The hacker only took down my home page so it was an easy fix but I have no idea if he put other files out there. I had this happen years ago and at that time there was something I needed to fix in my code.
Thank you very much.