Has anyone ever faced the issue of a PC or laptop responding to DHCP requests faster than the network DHCP server as a rogue DHCP server? There apparetly is no DHCP service running on this PC and we are currently looking to see if there is malware or something similar running on the PC. If the users look at the ipconfig, they may have a legitimate IP address and the DHCP server address looks correct but DNS is completely wrong. Release and renew will return the same IP address users originally received and seems to be a random thing. If we disconnect this PC from the network all further DHCP requests go back to normal.

Any way to protect the network from this type of traffic?