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Security Threats 3 Levels Beyond Kernel Rootkits

GhostX9 writes "Tom's Hardware has a long interview with security expert Joanna Rutkowska (which is unfortunately split over 9 pages). Many think that kernel rootkits are the most dangerous attacks, but Joanna and her team have been studying exploits beyond Ring 0 for some years. Joanna is most well known for the BluePill virtualization attack (Ring -1) and in this interview she chats a little bit about Ring -2 and Ring -3 attacks that go beyond kernel rootkits. What's surprising is how robust the classic BluePill proof-of-concept is: 'Many people tried to prove that BluePill is "detectable" by writing various virtualization detectors (but not BluePill detectors). They simply assumed that if we detect a virtualization being used, this means that we are "under" BluePill. This assumption was made because there were no products using hardware virtualization a few years ago. Needless to say, if we followed this way of reasoning, we might similarly say that if an executable makes network connections, then it must surely be a botnet.'" Rutkowska says that for her own security, "I don't use any A/V product on any of my machines (including all the virtual machines). I don't see how an A/V program could offer any increased security over the quite-reasonable-setup I already deployed with the help of virtualization." She runs three separate virtual machines, designated Red, Yellow, and Green, each running a separate browser and used for increasingly sensitive tasks.

4 of 264 comments (clear)

  1. Re:Well... by mlts · · Score: 4, Interesting

    This is something I'm wondering. Perhaps the best thing would be for the "Red" machine to be completely rolled back when done using, and have a virtual share mapped for any data that is worth saving.

  2. Re:Well... by Zerth · · Score: 4, Interesting

    That's what I've got on my setup now.

    After upgrading to a multi-core system where each had more processor and memory than my previous computer and noticing that 1 core was idle unless I was doing something CPU intensive, I virtualized my old machine and saved a snapshot just after bootup and opening a browser.

    Then I started using that in seamless mode instead of a browser. Every time I close it, not only is the browser history/cache/etc wiped, every possible change to the entire system is wiped.

    It doesn't run AV because that system just doesn't matter anymore. Instead of restarting my browser, I'm effectively wiping & re-installing whenever it feels laggy or "off".

    Perhaps it is a false sense of security, but as long as it is firewalled from the rest of the network and there isn't a "Neo" virus that can "escape the simulation", I feel safer than browsing on the host system with all the AV/noscript utilities running.

  3. Re:Better solution: read only media by Enleth · · Score: 5, Interesting

    Been there, done that, works great.

    A few years ago, I set up a bunch of thin clients for general browsing, chatting and homework at a school dorm - they were (were, as I have no idea if they're still in use, but they were absolutely maintenance-free, so I guess they should be) running Linux, with the kernel and boot config (generated on the fly) loaded from a read-only TFTP server and / mounted from a read-only NFS share. On each boot, the init scripts would finish generating a machine-specific configuration in /etc/ and mount a few ramfses on top of some directories using unionfs to give an illusion of a read-write filesystem. Then, upon login (LDAP authentication), the user's directory would be mounted from an individual password-protected Samba share (accessible from the users' personal computers as well), with the noexec attrubite of course. /tmp/ and /var/ were also noexec. Upgrades to the client system were performed at the server, by chrooting into the exported root directory.

    Such a configuration is absolutely invulnerable to users, rootkits, viruses and any other riffraff known for breaking things in computers. Even in the unlikely event that someone gained root privileges on a client, they would actually gain nothing and even that nothing would vanish after a reboot.

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  4. Re:o.k. by Runaway1956 · · Score: 4, Interesting

    You're serious, right? Let's assume that I have one copy of WinXP - or, Win7, legally licensed. I install a *nix as my primary OS, create a VM using VirtualBox, and I'm legal, so far, right? Get the VM all updated, then clone it 99 times. Suddenly, I'm illegal, right? But, all 99 machines are being used INSIDE of ONE BOX!!! I use one machine to browse the darknet, another machine to do torrenting, another to do my banking, one for general browsing, and one just to test malware on. The rest I may or may not ever fire up for some reason that I haven't thought of yet.

    So, how much should I mail to Microsoft for all of my VM's?

    Say, can I bum a dollar?

    --
    "Windows is like the faint smell of piss in a subway: it's there, and there's nothing you can do about it." - Charlie Br