ntdsapp.dll is a Trojan.Agent-FN. ntdsapp.dll opens a back door. Related files: %System%\ntdsapp.dll %System%\stivc.exe %System%\delttsul.exe %System%\imgcom.dll More info: http://www.sophos.com/virusinfo/analyses... Removal: Remove ntdsapp.dll from Windows startup using antivirus (also check How To Remove section)Startup Optimizer.