Scratch between TV LED and Backlight panel?

Hi guys, first timer here!

I recently noticed these things on my Sony 55" X800E. They appeared out of nowhere, at first I though it was a scratch or hairs in front of the panel, but after close inspection these seems to be behind the pixels, only noticeable if the picture is dark or black, they are about 1 inch long and now I can't unseen them every time I watch TV or play video games.

My TV is about 2 years old, I think it is still under BestBuy's extended warranty, but I'm not sure if this will be covered, whatever it is.

What do you guys think?

Thank you!