I have the same problem with the same model.
My tv is out of warranty by a year. It started as a small band of red dots in the upper right corner and it now has migrated to the rest of the screen. This only happens on light colored screens.
I had a tech come out and say it's a bad panel that it would cost $1,800 to repair it! That's more than I paid for it. I just contacted Samsung about this issue and mentioned a statutory warranty because a less than 2 year old tv should not be trashed this quickly! I'm waiting for them to contact me. If I were you, I would call Samsung and report the issue. The tech tried to claim that they've experience no issues with this particular model, but a quick internet search would prove different.