If you google the domain it looks like it was compromised by some guy who owns the instagram account mwr and goes by 'SLNTAR' as seen in a mirror of the website from May 18 2018. It looks like the owner of the website has regained control but it's possible the website is still under the attackers control.

Keep in mind it's possible that the person using it now isn't the same person as SLNTAR as it appears SLNTAR just runs a bot and hacks websites en masse by the looks of it.

edit: also looks like there was another scam on this website pretending to be an ico preregistration

If the website owner isn't the culprit it's likely he can still get the server logs and send the IP of the operator accessing it -- however, by the looks of it he is some Vietnamese dude selling illegal clothing dupes, so that's fun

extra edit: It actually looks like the website might be owned by a Vietnamese company that sells kitchen appliances based on the whois information. It appears this is a legit business with a physical location in Vietnam. If you can somehow get someone who knows Vietnamese to help you get them on board your investigation it is likely that there are log files which will COULD give you more information on whoever is doing this. They have a facebook page @ https://www.facebook.com/maxpara[dot]vn and the email listed on the facebook is minhhuy.maxpara@gmail.com