The hackyourselffirst.troyhunt.com website has now moved to hack-yourself-first.com. In order to still serve this website over insecure HTTP connections whilst also ensuring troyhunt.com could be HSTS preloaded, I had to add the "includeSubdomains" keyword which would mean no longer being able to serve the vulnerable site insecurely which is an important part of this project. Everything is still fully functional on the new domain so jump over and take a look at vulnerable site instead.