Q: How the system is protected from hacking?A: The same as every other system on earth?  Proper network security such as Firewalls. Proper host security aka Minimizing risks through configurations, updates, strong passwords, good practices, etc.  Patches to fix discovered bugs/flaws.Q: What will advise to take to protect osticket placed on the virtual server or hosting (settings and etc.)?A: This appears to be the same question as the first one.  Please see that answer.