It's legit. Informational website about ransomware and what to do in case your device is affected. Apparently sponsored/endorsed/whatever by Europol, the Dutch Police, Kaspersky, Intel, AWS and Barracuda.
If someone has a vulnerability that will break out of your web browser's sandbox, they're not going to waste it on this site.
And the ransomware that can be decrypted with this site is because of the author's incompetence. It's not hard to write secure ransomware, but they somehow failed very badly. Anyone should be able to easily protect this site.
