Thank you, but alas Steam said it is the key to Pandemic - On the Brink: Roles and Events :)

P.S. Fortunately, I don't have Pandemic, the key survived :)

P.P.S. As I see, the winner of actual Pandemic DLC GA marked key as received, so the actual Spider's Web DLC key hardly survived the mess :)
I give the permission to delete this giveaway, in advance.