It's square space. They don't have a great generic report form, but abuse@squarespace.com is acceptable for generic report.

https://www.squarespace.com/acceptable-use-policy

Defines their acceptable use policy, which this site is clearly in violation of.

The site currently resolves to the IP addresses 198.49.23.144 198.185.159.145 198.49.23.145 198.185.159.144 Which are owned by square space.