At this moment VPL can’t handle binary files. This feature is in the VPL TODO list. There is a workaround for this problem: you can code the content of a binary file to (for example) base64 and decode the file content in the server. The problem here is that you need to change the default script to decode the file. In the next VPL release, the decode process will be added in the default script and all the files with b64 extension will be decoded to a binary file with the same name but with the b64 extension removed.
I hope that this help.