antiav_dll.dll is a Trojan.Lodav.A. antiav_dll.dll tries to terminate antiviral programs installed on a user computer. Related files: %System%\antiav_exe.exe %System%\antiav_dll.dll Adds the value: "auto__antiav__key" = "%System%\antiav_exe.exe" to the Windows startup registry keys. More info: http://securityresponse.symantec.com/avc... Removal: Remove antiav_dll.dll from Windows startup using antivirus (also check How To Remove section)Startup Optimizer.