TBH I never considered the security aspect of asking people to load a strange webpage without their trusty Avast security extension to protect them. But now I do I can see the funny side.
Coriolis.IO is a much used and very useful website associated with the game Elite:Dangerous and, to the best of my knowledge, has no nasty surprises in store for the unwary. I've been using it for years. Those for whom this is insufficient reassurance will no doubt avoid it.