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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.'"
From TFS:
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.
So what's the difference between this botnet data, an SSL connection to a bank, or an encrypted email/file?
The answer is you can't tell, and neither can the ISP.
"What about the volume?" Encrypted Bittorrent.
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...
Sure you got rid of the TDL-4, but what about all the other crap it downloaded? Seriously, if the computer got owned, you can't trust it anymore. You'd never be able to find all the little things like permissions changes and registry tweaks even if you got rid of the trojan's executables. Copy your data files off, scan them really well before introducing them elsewhere, and then reformat the disk. Nuking it from orbit is the only way to be sure.