U3-Pwn is a tool designed to automate injecting executables to Sandisk smart usb devices with default U3 software install. This is performed by removing the original iso file from the device and creating a new iso with autorun features.
You can download it from the following link: https://packetstormsecurity.com/files/download/123555/u3-pwn-2.0.tar.gz
Source: https://packetstormsecurity.com/files/123555/U3-Pwn-Sandisk-Executable-Injection-Tool-2.0.html