Asubnet on your network uses dhcp for address assignment. the current scope has start address 192.168.1.1 and end address 192.168.1.200 with the subnet mask 255.255.255.0. because of network expansion, you have added computers, bringing the total number that needs dhcp for address assignment to 300. you don’t want to change the ip addressing scheme or the subnet mask for computers already on the network. what should you do?

Well depending on what kind of hardware you have available, you could simply create a second class C address range of 192.168.2.1, configure your DHCP server to issue IP Addresses on the new IP Addresse range and create a route between the subnets on a network router or switch (or you could even create the route on the DHCP server itself if you really wanted to). That way,you've expanded your scope without changing the existing IP addresses scheme or subnet mask for existing DHCP clients and all of the computers on your network can still communicate with each other.

Malware, not sure what else would fit that description.

You probably find kind your i think