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