Well.. first thing is to disable autorun, then you might want to access the pendrive via system console.
there I suggest you to do a dir /a to see what's actually in there, after that proceed to delete unwanted files, starting by autorun.ini
Anyway, if you can create a compressed file with all of the pendrive's content, you can sumbit it to AVERT lab so they provide a extra.dat for you (wich can be deployed via ePO) and eventually will be included in a official DAT Release.