Versions

5,6,169,0	52.73%
5,6,169,0	23.64%
5,6,153,0	7.27%
5,6,138,0	1.82%
5,6,133,0	1.82%
5,0,208,0	1.82%
5,0,208,0	5.45%
3,15,101,0	1.82%
3,11,100,0	1.82%
3,0,216,0	1.82%

mcnmcsrv.dll has 10 known versions, the most recent one is 5,6,169,0. The average file size is about 1.42 MB. It is an authenticode code-signed executable issued to McAfee by the certification authority VeriSign.

The Network Agent is a subsystem of the Home Network product. It works by communicating with certain windows systems that have ports open on your network. It does not do a full port scan, rather, it targets specific ports to determine what type of machine is connected to your network. An example of this is the SMB probe which determines if the machine is running windows. Other protocols and ports that are supported by Network Agent are UPnP, HTTP, ARP, and Apple's Bonjour.