Update: Dan just let me know that Tillmann Werner and Felix Leder have been working on this for 5 months! Dan came in (and then brought me in) only on Friday. They deserve major credit and thanks for this impressive work. Also, Nmap (which is still free) and the free feed of Nessus have their signatures out for those of you that don’t have an enterprise product.

Ever since last year, I always get a little nervous when Dan Kaminsky starts asking me certain questions over Twitter. Last time it was the DNS vulnerability, and this time it was something not as big, yet still extremely cool.

Some researchers with the Honeynet Project (Tillmann Werner and Felix Leder) discovered a way to remotely (as in via network scan) detect Conficker infections. It seems that whoever is behind Conficker attempts to patch the MS08-067 vulnerability when they infect a system so no other attackers can get in. The patch is flawed, causing a specific response to network probes. Yes folks, this means you can tell if a system is infected with Conficker just by scanning it. Now how cool is that?



p>The HoneyNet guys contacted Dan for some help, and then he contacted me to get connected with the major scanning vendors. I called Adrian, and we managed to wrangle up nCircle, McAfee, nCircle, Nmap, Qualys, and Tenable (Nessus) and most have already incorporated, or are about to incorporate, Conficker sigs for their scanners. I think Dan is giving me too much credit in his post; all I did was connect the right people with each other; I wasn’t involved in the tool creation or testing. (We did shoot for some other vendors, but didn’t have the right contacts).

I know Dan, the HoneyNet guys, and the vendor research teams all put in a heck of a lot of time on this over the weekend.

Here’s what you enterprise guys need to know:

  1. There is a free proof-of-concept tool available from the HoneyNet Project, or you can contact your network vulnerability assessment vendor to see if they have an updated signature.
  2. This should work on all Conficker variants. (I suspect that won’t last long).
  3. The “Know Your Enemy” paper will be released by the HoneyNet Project in the next couple of days, with far greater detail.
  4. This doesn’t guarantee you will detect all infections, but it’s a powerful way to reduce your risk. We recommend you start scanning immediately if you have the slightest worry over Conficker.
  5. Expect the tools to undergo a series of updates in the next few days as we all learn more. This really is hot-out-of-the-oven stuff that still needs to settle in.
  6. The next phase will be to include this in NAC products for pre-connect scanning.

That’s about it- simple enough! If you start using these and find anything interesting, please come back and post it in the comments.