Conficker's Three-Way Knockout

Malware analysis is a highlight of what I do, but it's not something I get to do on a weekly basis. The cases I deal with are a bit sporadic and clustered, showing an obvious ebb and flow based on current trends. This is one of those heavy times, thanks to Conficker and its friends.Conficker, a.k.a. Downadup, is truly wreaking havoc on some enterprises. Can you imagine being a patient at a hospital that was plagued with more than 800 infected computers? (See "Conficker Seizes City's Hospital Network.") According to The Register article, management suspended automatic updates for Windows hosts after some machines in an operating room had rebooted during surgery.

Knee-jerk reactions like that aren't uncommon, but I can't say I've heard of any that almost immediately resulted in the compromising of nearly 1,000 machines. Who ends up with the egg on their faces? Management or IT? Yeah, probably IT.

The past six months have been full of other similar stories in terms of the numbers of compromises. Cornell University, for example, found more than 1,000 machines infected on its campus network. The problem was so rampant that it set up a dedicated Website to inform users and sponsored walk-in clinics to help clean machines and infected USB thumbdrives.

What I find most interesting about Conficker, specifically, is that even though it has amazing capabilities for patching the MS08-067 vulnerability in memory, how it has been executed (to thwart malware analysts), and how it deletes System Restore Points -- the freaking thing uses old school techniques to spread.

Infecting machines via removable media has happened since the days of floppies. Exploiting Windows services is nothing new. Neither is spreading to other hosts via brute-force password on Admin shares. It has all been done before. How is it that we're hearing of such staggering infection numbers?

It comes down to a three-way whammy. In the case of the hospital, machines were infected through the MS08-067 vulnerability. Those that couldn't be exploited probably had the same local administrator password that could have been broken. And, in the case of Cornell, whether or not it was Conficker, it was definitely spreading via autorun capabilities in USB flash drives.

I don't know about you, but I'm ready for another malware lull. It has been a busy six months, and there's no signs that things are going to get easier. Good luck out there!

John H. Sawyer is a senior security engineer on the IT Security Team at the University of Florida. The views and opinions expressed in this blog are his own and do not represent the views and opinions of the UF IT Security Team or the University of Florida. When John's not fighting flaming, malware-infested machines or performing autopsies on blitzed boxes, he can usually be found hanging with his family, bouncing a baby on one knee and balancing a laptop on the other. Special to Dark Reading.