There's no viruses on them, but as TU said, the nature of a 4k program means that anti-virus programs sometimes detect them as viruses. These would be very useful for 3d previews, especially as Planetside doesn't especially need it to fit into 4KB, so the processing power required to execute what is essentially a mass of mathematic algorithms wouldn't be as prevelant. I reckon the same techniques within a size limit of about 30MB would be astounding.