PPWSE Appears to have been hacked!!

[rowlandmedia]

We have a site on our server that is using PPWSE. In the PPWSE directory there is a folder that is called .data and is getting filled up with what appear to be or some sort of video files for torrent download (I assume). Is there an exploit for PPWSE we have not patched? I need to know what this exploit may be and how to plug it. I have been unsuccessful finding anything on the net referencing it. Any assistance is appreciated.