Oh dear, it was about time it happened.
But if you have been around itch.io comment sections for a bit, you may have noticed people spamming comment sections with links to games.
And it doesn’t take long to realise that, it’s “stolen” games.
These individuals grab an existing game, package it full of malware, upload it to itch.io and then spam comment sections in order to bait people into downloading. Some times it’s not even itch.io games, which might make it more passable, but either way it’s still shady for them to do nothing but spam links. It’s against itch.io’s guidelines.
At least they’re wise enough to not spam the comment section of the game they’re stealing from…
As for your case… I don’t really know.
Run Windows Defender and maybe Malwarebytes. Other than that, I don’t really know, hopefully it didn’t do much damage.