When I come in to work every morning I follow a standard routine. First, I make sure to grab some coffee and fruit down at the cafe. I then check my email, voicemail, calendar, etc. and plan my day accordingly. Next, I catch up on the news – technical, political, weather, security, sports, etc. Trite, cliche, boring eh? Well, the way in which I go about accessing the Internet is somewhat unique….
A colleague of mine recently turned me on to the concept of ‘ephemeral desktops’. The idea behind ephemeral desktops is simple. The reality is, an attacker can catch any one of us snoozing at any given time. Maybe clickjacking? Perhaps drive-by downloads? Phishing malware? etc. Inevitably, every organization at some point or another will have an employee fall prey to persistent malware and put their company’s network at risk. Ephemeral desktops are a great tool for mitigating persistent malware threats. How do they do this? What exactly does this mean?
Getting back to my daily routine…before I check the news, I load a custom Ubuntu 9.04 live CD (that my colleague has put together). This Ubuntu live CD is read-only with a few useful applications to assist me in doing my job including both SSH and VPN clients. The idea behind the ephemeral desktop, in my case the tinkered with Ubuntu live CD, is that nothing can be written to disk. This means, no persistent malware can be written to disk because I am manipulating the Internet with a browser on a read-only CD. Perhaps, while using my ephemeral desktop, I browse the Internet and accidentally download some form of persistent malware. It really doesn’t matter. The next time I boot from my Ubuntu live CD I will be starting, once again, from a clean state. I can lose the battle but still win the war.
The idea behind lightweight, ephemeral desktops, is auspicious considering the direction we are headed with the cloud. As for virtual environments, users require a client to interface with a particular environment. Currently, virtual environments rely too heavily upon these clients for functionality (scripting and condensed physics engines). It may be interesting to pursue research concerning ephemeral clients (with similar principles to the ephemeral desktop) that will always start from a clean state. Despite what malicious content may or may not have been downloaded from a previous virtual experience, a user can trust that no persistent malware has been written to their disk.