I did download it at the end of the day and nothing has happen...
It's not a malware - my own windows defender doesn't get triggered and Virus total doesn't find anything either.
Concerning the problem with the game page, I opened a ticket with itch.io support. I hope it will get resolved soon.
EDIT : problem solved. Page got randomly flagged by some itch.io algorithm (false positive), but it's now back at normal. Nothing we could do but wait......