Fun with bash, libguestfs, rkhunter, and academics.

I recently completed my Masters Degree in Information Assurance and Security which was an amazing experience and I'm so excited to have it completed but that's not the focal point of my blog post. As the walking/talking Fedora fanboi that I am, I did my best to incorporate as much Fedora technology and Open Source Software into my studies as humanly possible. I was extremely fortunate to have a Faculty Advisor who was willing to indulge my Open Source agenda. Along the path of my studies, one thing I found extremely interesting is libguestfs which is primarily (or possibly solely) authored by Richard WM Jones who is a ninja for writing this thing in the first place but was also extremely helpful to me in irc when I was trying to sink my teeth into libguestfs for the first few rounds, so many thanks to him.

I had this idea about private IaaS cloud environments where your cloud infrastructure administrators might not have root access to the VMs running within their datacenters but they still wanted to provide some level of security audits from the hosting side. Now, we can check for exploits running on these systems with standard tools such as nmap, nessus, metasploit and more but what about checking for malicious files on the filesystems themselves? Rootkits? Viruses? $other? Well, this is where the amazing power of libguestfs introduces itself because we can access these things in read-only mode from the level of the hypervisor (which in the case of KVM is/can be a full featured, full fledged OS as it is a hosted hypervisor) without even an account on the virtual machines.

So what can we do with this? Well, I'm sure there are an endless number of possibilities as there often are with topics of this nature but I decided to write a fun proof of concept bash script (there's some awk and coreutils in there, but I generally just lump the family of *nix utils together with "bash" script claims) that will run rkhunter against libvirt guest domains and create a report with a report ID that can be called later to view the report. Now, I'll admit this is not the most elegant implementation of a reporting mechanism because I'm essentially tagging the beginning and ending of a report entry in a text file and running awk across it to produce some basic information about the run but its a proof of concept and its functional! :)

I also wrote a man page and a nice little ncurses (dialog) UI for it, here's some screenshots for kicks:

I titled it gaudit which stands for "Guest Audit" but if someone ever decided to write a tool and wanted the name you're more than welcome to it. I don't plan to have this go anywhere beyond what its done thus far, it was just a lot of fun and I thought I'd share my exploration. Oh, and here's some code. I rolled a rpm as well, SRPM available also.. :)

Source(browse): http://maxamillion.fedorapeople.org/gaudit-0.1/
Source(tar.gz): http://maxamillion.fedorapeople.org/gaudit-0.1.tar.gz
SRPM: http://maxamillion.fedorapeople.org/gaudit-0.1-1.fc16.src.rpm
RPM(noarch): http://maxamillion.fedorapeople.org/gaudit-0.1-1.fc16.noarch.rpm

Like I said, its just a proof of concept but it was a lot of fun to hack on, I hope someone somewhere might find it interesting and maybe ignite an idea to take the general concept further to build a really cool utility! :)

Happy Hacking,
-AdamM