diagent.exe is a Trojan W32.Agobot-CW. diagent.exe opens a back door on IRC channels. diagent.exe spreads via open network shares. Related files: %System%\winpn32.exe %System%\diagent.exe More info: http://www.sophos.com/virusinfo/analyses... Removal: Kill diagent.exe process and remove diagent.exe from Windows startup using antivirus (also check How To Remove section)Startup Optimizer.