Skindex used to be legitimate, but it fell out of favor with PMC. When Minecraft withdrew from the public eye, this only hurt them more from my understanding, which ultimately brought them down for good (It used to be Skindex.net, which is now an available domain to buy). Skindex.com was bought by... something. An ad farm, maybe? I'm not sure. It's definitely unregulated and running hog wild.
Anyways, to OP, Skindex is already gone. Someone's just wearing the mask.
