we all know about china virus.i need script run every 2 min that find mac who changing ip in hosts and block mac
i’m sorry, but I don’t know about china virus 
what is it?
china virus make mac chang ip
A PC changes it’s IP all the time? Doesn’t sound like much of a virus.
Lock the MAC to the IP for all users. Nobody will be able to change the MAC or IP then.
Or use PPPoE - much better solution.