I am very happy to report that I am back online! Thanks to the wonderful staff at Linode we were able to determine that the comprise was a result of a misconfiguration of dnsmasq. In this particular case dnsmasq was acting as an open resolver which allowed an attacker to use the node as part of a DNS amplification attack. The solution was as simple as removing dnsmasq from the server and rebooting the node. To remove dnsmasq all I did was run the following command:
apt-get autoremove dnsmasq --purge
I really couldn't be happier with the assistance the Linode staff provided and as I have said in the past I highly recommend them for all of your hosting needs.