Obviously video data files can't be infected any way, but same obviously they were not able to backup Terabytes of data from multiple servers.
So prepare your old files for reuploading, I believe it's the only possible way to get back in business.
Nice try, dear, but oviously this hack have nothing to do with XVideoSharing script this time. Please don't mention them to avoid extra attention.
Sure developing from zero stage is the best way to avoid known vulnerabilities, but this can take months, GU don't have this time gap now.