qz.dll is a Trojan Backdoor.Haxdoor.E. qz.dll tries to terminate antiviral programs installed on a user computer. qz.dll monitors user Internet activity and private information. It sends stolen data to a hacker site. Related files: %System%\avpx32.dll %System%\qz.dll Adds the value: "DllName" = "avpx32.dll" to the Windows startup registry keys. More info: http://securityresponse.symantec.com/avc... Removal: Remove qz.dll from Windows startup using antivirus (also check How To Remove section)Startup Optimizer.