In our previous technical analysis of the ZeroAccess rootkit, we highlighted how it acts as a framework by infecting the machine — setting up its own private space in the disk, first through a dedicated file system on the disk, and more recently by using a hidden and locked directory. This is where the rootkit stores the modules it downloads from the command and control servers. Until now, the plugins we’ve monitored have been ad-clickers and search engine hijackers.
We have also noted how the ZeroAccess rootkit acts very similar to the TDL3 rootkit, either by infecting a random system driver, using its own file system to store its plugins or by filtering the disk I/O by analysing the SCSI packets – though in a pretty different way. It’s more effective in the TDL3 rootkit and less effective in the ZeroAccess rootkit, however ZeroAccess has many more self-protection mechanisms in place.
While analyzing the ZeroAccess rootkit, I’ve always had the feeling it was inspired by the TDL3 rootkit. But while looking at the latest updates of it I’ve found something pretty interesting: The ZeroAccess team is looking at TDL rootkit as an enemy that needs to be defeated. The questions remains, is there a link between the two rootkits? We suspect the answer is yes.
The Black Hat briefings, held Wednesday and Thursday this week, once again brought together some of the best and brightest in the security industry to share knowledge about novel attacks and better defenses against old and new attacks. And, once again, there were some eye opening moments at the conference.
Right from the beginning, it was clear the scope of the conference had shifted from the previous year. Conference founder Jeff Moss described a new, more rigorous committee-driven process that Black Hat had begun to employ to scrutinize and vet talk proposals. Talks this year would be more technical, go deeper into security threats, and would encompass a broader range of topics than had been done in years past.
But soon after Moss introduced former ambassador and CIA counterterrorism expert Cofer Black, the opening keynote speaker to the conference, someone pulled a fire alarm in the hall where the speech was taking place. While lights flashed and warning sirens sounded, Black joked about the prerecorded messages playing over loudspeakers.
There are fewer types of malware infections more frustrating and annoying than a rootkit with backdoor capabilities. Over the past couple of years, we’ve seen the emergence of this new, tough-to-fight infectious code, and its transformation from nuisance to severe threat.
With the hard work and perseverance of Threat Research Analyst and master reverse-engineer Marco Giuliani, we’re proud to release the latest build of a tool we’ve used internally to clean the infections from the notable ZeroAccess rootkit off of victims’ computers. AntiZeroAccess exploits many of the vulnerabilities that Marco discovered in the rootkit to cleanly remove the rootkit code from infected machines.
The free tool removes the rootkit but does not restore the Access Control Lists (ACLs) that have been modified by the rootkit. For that, you’ll probably want to use a free tool like SetACL, which can make software functional that ZeroAccess disabled by modifying its ACL.
As I do every year, I’ve deliberately traveled to the most inhospitable climate zone in the continental US — that is, the city of Las Vegas — to attend the elite technical conference known as the Black Hat Briefings.
Black Hat is not just a technical conference, but a kind of calling for its attendees, which brings together experts in computer security, privacy, and attacks with high level officials in government and industry. In this rarefied environment, the security industry and its benefactors share information, tools, and techniques that help the entire industry coordinate their work against the interests of criminals, spies, and the vast numbers of Internet ne’er-do-wells.
I’ll be reporting from the conference about cool tools, new information about attacks, and deep analysis of malware all week. On Friday, the conference switches gears to become Defcon, which is a little less formal, a little less businesslike, and a lot more chaotic and interesting. Stay with us this week as we cover the most interesting conference in the security world.
Among the most infamous kernel mode rootkits in the wild, most of them have had a slowdown in their development cycle – TDL rootkit, MBR rootkit, Rustock are just some examples. The same doesn’t apply for the ZeroAccess rootkit. The team behind it is working quite hard, which we know for a fact because I’ve seen it.
We already talked about this rootkit and its evolutions in several blog posts, along with a white paper that documents more in depth all the technical features of the malware. The last major update released by the team behind ZeroAccess dates back a couple of weeks; That update implemented a strong self-defense routine able to kill security software programs that try to get access to its code, blocking the security software from running by manipulating access control list, or ACL, settings.
Last week ZeroAccess received another update, and again it’s a major one. The rootkit shifted from a hidden encrypted file used as an NTFS filesystem volume to a more comfortable hidden directory created inside the Windows folder, where the rootkit still stores its configuration data and other malware in an encrypted form. Continue reading →