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Massive Botnet "Indestructible," Say Researchers

CWmike writes "A new and improved botnet that has infected more than four million PCs is 'practically indestructible,' security researchers say. TDL-4, the name for both the bot Trojan that infects machines and the ensuing collection of compromised computers, is 'the most sophisticated threat today,' said Kaspersky Labs researcher Sergey Golovanov in a detailed analysis on Monday. Others agree. 'I wouldn't say it's perfectly indestructible, but it is pretty much indestructible,' Joe Stewart, director of malware research at Dell SecureWorks and an internationally-known botnet expert, told Computerworld on Wednesday. 'It does a very good job of maintaining itself.' Because TDL-4 installs its rootkit on the MBR, it is invisible to both the operating system and more, importantly, security software designed to sniff out malicious code. But that's not TDL-4's secret weapon. What makes the botnet indestructible is the combination of its advanced encryption and the use of a public peer-to-peer (P2P) network for the instructions issued to the malware by command-and-control (C&C) servers. 'The way peer-to-peer is used for TDL-4 will make it extremely hard to take down this botnet,' said Roel Schouwenberg, senior malware researcher at Kaspersky. 'The TDL guys are doing their utmost not to become the next gang to lose their botnet.'"

6 of 583 comments (clear)

  1. Re:Take 'em offline by the_bard17 · · Score: 4, Interesting

    Just throw a clause in the Terms and Conditions that states the subscriber is required to maintain an outgoing connection free of malware. Otherwise, the ISP gets to redirect all traffic to a "Hey, you're infected!" page for the duration.

    The first time the subscriber calls in to say it's rectified, remove the redirection and monitor it. The second time, be nice and request some proof. The third time, require a faxed copy of a receipt/invoice/statement from a third party verifying that all the connected in the residence are clean and all wireless networks are encrypted securely. Rinse, lather, repeat.

    It seems the T&C is being used as a catch all for all the other shady business telecom's are pushing down our tubes... may as well as use it for a bit of good, too.

  2. Not impossible by Anonymous Coward · · Score: 4, Interesting

    I work at a computer repair shop.

    We frequently encounter computers that are kitted up with boot and rootkits, TDL-4 included. Kaspersky's TDSS killer does a pretty good job of removing this stuff, and it's pretty easy to tell if the MBR as been modified. Just fire up a copy of GMER and you'll be able to tell pretty quickly. I see a lot of people posting stuff about having to wipe drives and start over from scratch. That is simply not necessary. The only reason TDL-4 is such a pain in the ass is because it is decentralized, only communicates with a handful of its infected counterparts at a time and modifies the MBR. Even then, it's not impossible to detect or even remove. Just gotta use the right tools...

  3. I knew this was going to happen by Omnifarious · · Score: 4, Interesting

    Curious Yellow was bound to happen sooner or later. I was wondering what was taking botnet authors so long, and why they were relying on a centralized system like DNS for coordinating their bots.

  4. Re:Command and Control by pclminion · · Score: 4, Interesting

    You can sign the patches and make it impossible to inject update packets straight into the botnet. A more plausible line of attack would be to find a traditional security vulnerability and exploit it.

  5. P2P is also its weakness by Dachannien · · Score: 5, Interesting

    The fact that the software maintains itself peer-to-peer is also its greatest weakness, because it allows any infected node to identify other infected nodes. So, you set up a number of honeypots and use those to identify infected machines. You then strongarm those machines' ISPs to disconnect their customers until they get their shit together.

    Yes, the whole "strongarming the ISPs" thing is a flaw in the strategy since it hasn't really been successful to date, but I'm sure Microsoft can come up with a legal solution to that little hitch.

  6. Re:Invisible? by cgenman · · Score: 4, Interesting

    Unfortunately, most people who are running a modern version of Windows are doing so because it came on the computer they bought it on. I say unfortunately, because I have yet to see a computer ship with anything but those damned useless "restore" DVD's. It can't fix your system, or perform routine maintenance tasks, or anything useful. And if you've make any alterations to your hardware setup, you can forget it.

    Shipping without an install disk for a paid for pre-installed OS that bundles lots of routine OS functionality on its install disk should be illegal. Or, rather, it should be legal to pass around copies of the install disk to everyone who has the OS.