cmdagent.exe is a Comodo Agent Service from Comodo belonging to Comodo Firewall.
The Cmdagent.exe file belongs to the Comodo Firewall and is known to cause 100% CPU usage problems on Windows computers. Additionally, if you try to end the cmdagent.exe process from the Processes tab of the Task Manager, you may get an “Access Denied” error message. You get this message because the file is part of the Comodo Firewall, which might be functional when you try to end the cmdagent.exe process.
Various methods have been proposed as a solution to resolve the high CPU usage problem by the cmdagent.exe file. However, before implementing any of these you should ensure that the cmdagent.exe file you have is legitimate. The correct location of the file is C:\Program Files\Comodo\Firewall\CPF.exe. If you find the file somewhere else, be warned that it may be a virus, a Trojan or some other form of malware.
Another warning sign to look out for is file size. Known file sizes of cmdagent.exe on Windows XP are 361040 bytes, 495360, 565840, 544512, 569936 and 356944 bytes. If the file that you see is located in a different folder and/or has a different file size, you should approach it with caution.