Somebody says this is a fake.
I looked at the picture in PS and if this is a fake, then it is a very very good one.
The only thing that looks strange for me is the font family used for this lens (look at 24-70mm inscription). It seems to be a new one and not the same like for Canon 24-105, 24 f1,4 and of course 24-70.
Maybe it is nothing ...