It's a Sony Xperia L1 and the scorch marks appeared a month or so ago. But now another one has appeared so there are two, one on each side of the screen.
just moved your post to the correct section of the forum.
As for the issue, do the screen looks yellowish? that's usually stress related and/or water damage, but since it's a hardware issue, it'll be wise to get it inspected with your local support
also, take a screenshot > send it to another phone or computer > do you see the scorched marks?
Auto-suggest helps you quickly narrow down your search results by suggesting possible matches as you type.
