There is a video on YouTube about Hyundai filters. They example they give is to check the wording on the can, unfortunately it's in Korean. I have also seen one webpage about the subject, but the example they gave was the same.
I think you should be able to tell with a high degree of accuracy if you just look down the center tube. The filters I have in stock have the Hyundai symbol on the bypass valve, and you can easily see through the center tube that media has nice even pleats, and it looks like there is a lot of it. Based on the examples of counterfeit filters, you should be able to tell the difference.