Get the Whitepaper called Effectiveness of Antivirus in Detecting Web Application Backdoors.
You can download it from the following link: https://packetstormsecurity.com/files/download/98021/av-effectiveness.pdf
Source: https://packetstormsecurity.com/files/98021/Effectiveness-Of-Antivirus-In-Detecting-Web-Application-Backdoors.html