USB Memory start up app.

Hi,

I have a little bit over 1500 USB pens that we bought from China, it came with a small application that auto start, all of them are infected with a trojan Virus, we tried formatting, deleting the partition etc., and nothing, the startup application it's still intact, it almost feels like it's burned in to the microchip or a bios, Is there something we can use to wipe it clean.

Any help will be greatly appreciated

Norm.