'Invisible' rootkit heralds trouble ahead

Security researchers have discovered a new type of rootkit they believe will greatly increase the difficulty of detecting and removing malicious code.

The rootkit in question, called Backdoor.Rustock.A by Symantec and Mailbot.AZ by F-Secure, uses advanced techniques to avoid detection by most rootkit detectors.

The rootkit is "unique given the techniques it uses," Symantec's Elia Florio wrote in a recent analysis. "It can be considered the first-born of the next generation of rootkits."

Rustock.A uses a mixture of old techniques and new ideas to make it "totally invisible on a compromised computer when installed," including a beta version of Windows Vista, Florio wrote.

Symantec believes the rootkit originates from Russia, and a string found in the rootkit's code indicates new versions will probably be forthcoming. Symantec has already logged a variant called Backdoor.Rustock.B.

F-Secure noted Rustock's use of NTFS' Alternate Data Streams (ADS) as one significant example of its advanced behavior.

"Saving your data into Alternate Data Streams is usually enough to hide from many tools," wrote F-Secure researcher Antti Tikkanen in a company blog.

"However, in this case, the stream is further hidden using rootkit techniques... because Mailbot.AZ is hiding something that's not readily visible, it's very likely that many security products will have a tough time dealing with this one."

F-Secure said it has released a new version of the BlackLight rootkit scanner, Build 2.2.1041, which can detect Rustock.

According to researchers, other factors that help make Rustock invisible are that it has no process, instead running inside the driver and in kernel threads. It doesn't hook into any native API, and controls kernel functions via special IRP functions. It removes its entries from kernel structures, and the SYS driver is polymorphic, changing its code from sample to sample.

Rustock also scans for loaded rootkit scanners, then changes its behavior to avoid detection, according to Florio.

Join the newsletter!

Error: Please check your email address.
Rocket to Success - Your 10 Tips for Smarter ERP System Selection
Keep up with the latest tech news, reviews and previews by subscribing to the Good Gear Guide newsletter.

Matthew Broersma

Techworld.com
Show Comments

Most Popular Reviews

Latest Articles

Resources

PCW Evaluation Team

Ben Ramsden

Sharp PN-40TC1 Huddle Board

Brainstorming, innovation, problem solving, and negotiation have all become much more productive and valuable if people can easily collaborate in real time with minimal friction.

Sarah Ieroianni

Brother QL-820NWB Professional Label Printer

The print quality also does not disappoint, it’s clear, bold, doesn’t smudge and the text is perfectly sized.

Ratchada Dunn

Sharp PN-40TC1 Huddle Board

The Huddle Board’s built in program; Sharp Touch Viewing software allows us to easily manipulate and edit our documents (jpegs and PDFs) all at the same time on the dashboard.

George Khoury

Sharp PN-40TC1 Huddle Board

The biggest perks for me would be that it comes with easy to use and comprehensive programs that make the collaboration process a whole lot more intuitive and organic

David Coyle

Brother PocketJet PJ-773 A4 Portable Thermal Printer

I rate the printer as a 5 out of 5 stars as it has been able to fit seamlessly into my busy and mobile lifestyle.

Kurt Hegetschweiler

Brother PocketJet PJ-773 A4 Portable Thermal Printer

It’s perfect for mobile workers. Just take it out — it’s small enough to sit anywhere — turn it on, load a sheet of paper, and start printing.

Featured Content

Product Launch Showcase

Latest Jobs

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?