impai.exe is a Trojan.Lewor-Q. impai.exe opens a back door. Related files: %System%\impai.exe %System%\wnilogon.exe More info: http://www.sophos.com/virusinfo/analyses... Removal: Kill impai.exe process and remove impai.exe from Windows startup using antivirus (also check How To Remove section)Startup Optimizer.