Eavesdropping on a Botnet

wild3rbeast writes "Joe Stewart, a senior security researcher with LURHQ's Threat Intelligence Group has figured out a way to silently spy on a botnet's command-and-control infrastructure, and finds that for-profit crackers are clearly winning the cat-and-mouse game against entrenched anti-virus providers. From the article: 'The lesson here is once you get infected, you are completely under the control of the botmaster. He can put whatever he wants on your machine, and there's no way to be 100 percent sure that the machine is clean. The only way to be [completely] sure the system is malware-free is to completely wipe the hard drive and reinstall the operating system.'"

Comments

Makes you wonder what else is going on

[perkr]

Spam is one thing, but once you got access to the machine, getting logins and passwords for online stock and bank account services via a keylogger is completely different. I wonder how much stuff is silently running on users machines right now...

Re:Makes you wonder what else is going on

[Pantero Blanco]

You'd also end up with many more dead cops, and much more sympathy for those criminals. If the penalty for dealing pot or prostitution was death or life in prison, I for one would offer safe haven and protection to pot dealers and prostitutes.

Re:It's a bird. It's a plane. It's TC!

[mrbcs]

Every game I buy, before installation, I go to gamecopyworld.com and get the no-cd patch. I friggin HATE putting the cd in every stinkin time I want to play a game.

Need to hold users responsible.

[Rotten168]

If you are a computer user, you are responsible for the problems they are creating. ISP's need to inform people they have bots and if they are infecting other computers they need their internet access dropped. Tough love.

Why do you rob banks?

[twitter]

... because that's where the money is.

You write about root kits and declare:

Just by the virtue of the large number of x86 Linux servers exposed to the Intarweb, there must be thousands of systems just waiting to be rooted. Fortunately for "us", there are millions of exposed Windows client PCs running as Adminstator, begging to be owned.

As if the only difference was numbers. The other difference, or so claim the FUDsters, is that "Linux is for servers." You know, like banks and businesses that handle real money. Given the profile and importance of those targets, you would think they would be hit all the time and that we would hear about it as we hear of IIS exploits. For some reason we don't hear anything, despite the very open nature of the people running the software. It would seem that there's more at work than numbers here.

On the desktop there's another crucial difference, the ease of recovery. In the Windoze world, you pull out your ancient "original" CD and put the same broken crap right back on your machine. It wipes out all your documents and setting so you suffer a loss for no gain. Then you are rooted again in about 12 minutes after hooking up to a network. In the free world, you do a net install and get the latest and greatest of everything, without losing anything at all. A few extra steps can make sure the root kit is not in your home directory. The easiest is to chmod file in your home directory to no execute. In the very worst case you can chmod and then tar up the documents you worry about and start fresh with your settings, like in the windoze world but much easier.

Re:Why do you rob banks?

[Anonymous Coward]

What do you think the C&C machines are running?

Linux servers, especially colocated ones, tend to have a much higher uptime; in addition, the ircds and other servers they run tend to run best (or only) on Linux. A Linux shell box is a lot more useful to a blackhat than a Windows drone. This makes them individually more attractive targets.

Imagine you're a blackhat. So what you're after, for a C&C server, is someone else's poorly-maintained Linux box; the one that the admin thinks is impenetrable, because it runs Linux, and so hasn't updated it or even looked at it in ages. It's going to have a high uptime, because it almost never reboots because the guy never installs a new kernel on it. You can probably spy out the uptime quietly in advance via the usual trickery, because some admin thought Linux boxes don't need firewalls. And you're most likely going to get in through a PHP hole (application or language, it doesn't matter when the language and common software is that poorly designed) or if it's really out of date an Apache or MySQL hole - because it's probably a almost-never-used webserver.

And then you're going to install a rootkit - think l10n, only more so (there are actually some seriously hardcore Linux rootkits that blow pretty much all of the public rootkits for Windows out of the water when it comes to stealth; and this is why) - and then you're going to patch it, so no-one else roots your new 0wned C&C box, because nothing sucks more than some other blackhat stealing your botnet.

Next thing you know, bam, the thing's running a modified hybrid-ircd or something, and is one of the magic servers you encoded in your trojan to which the Windows drones are connecting back, or one of the webservers they are getting the spam proxy or spyware installer from; and thus you, the blackhat, earning nice fat sums of cash on the back of one or two Linux servers and a few hundred or thousand random Windows machines.

So, don't discount the threat. All operating systems need patching and good security practice to run safely.

And 0.1% seems like a low estimate; remember Linux distributions, especially server-oriented ones, tend not to have an automatic update feature (with good reason, to a point), so they do require manual intervention to patch. With appropriate care and feeding they are of course not just fine, but can be really quite secure; but neglected, it's a whole different story. Think closer to 2-3% as being a potential problem, and almost 5% in some (LAMP) brackets.