'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!

Or

Sign up to gain exclusive access to email subscriptions, event invitations, competitions, giveaways, and much more.

Membership is free, and your security and privacy remain protected. View our privacy policy before signing up.

Error: Please check your email address.
Keep up with the latest tech news, reviews and previews by subscribing to the Good Gear Guide newsletter.

Matthew Broersma

Techworld.com
Show Comments

Cool Tech

Bang and Olufsen Beosound Stage - Dolby Atmos Soundbar

Learn more >

Toys for Boys

Nakamichi Delta 100 3-Way Hi Fi Speaker System

Learn more >

ASUS ROG, ACRONYM partner for Special Edition Zephyrus G14

Learn more >

Sony WF-1000XM3 Wireless Noise Cancelling Headphones

Learn more >

Family Friendly

Mario Kart Live: Home Circuit for Nintendo Switch

Learn more >

Philips Sonicare Diamond Clean 9000 Toothbrush

Learn more >

Stocking Stuffer

Teac 7 inch Swivel Screen Portable DVD Player

Learn more >

SunnyBunny Snowflakes 20 LED Solar Powered Fairy String

Learn more >

Christmas Gift Guide

Click for more ›

Brand Post

Shining a light on creativity

MSI has long pushed the boundaries of invention with its ever-evolving range of laptops but it has now pulled off a world first with the new MSI Creative 17.

Most Popular Reviews

Latest Articles

Resources

PCW Evaluation Team

Tom Pope

Dynabook Portégé X30L-G

Ultimately this laptop has achieved everything I would hope for in a laptop for work, while fitting that into a form factor and weight that is remarkable.

Tom Sellers

MSI P65

This smart laptop was enjoyable to use and great to work on – creating content was super simple.

Lolita Wang

MSI GT76

It really doesn’t get more “gaming laptop” than this.

Jack Jeffries

MSI GS75

As the Maserati or BMW of laptops, it would fit perfectly in the hands of a professional needing firepower under the hood, sophistication and class on the surface, and gaming prowess (sports mode if you will) in between.

Taylor Carr

MSI PS63

The MSI PS63 is an amazing laptop and I would definitely consider buying one in the future.

Christopher Low

Brother RJ-4230B

This small mobile printer is exactly what I need for invoicing and other jobs such as sending fellow tradesman details or step-by-step instructions that I can easily print off from my phone or the Web.

Featured Content

Product Launch Showcase

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?