Two malware programs help each other stay on computers

Microsoft says the Vobfus and Beebone malicious software programs are proving to be a pain

Two malicious software programs that help each other stay on computers are proving difficult to remove.

The programs work together by alternately downloading slighter different variations of the other in an attempt to evade antivirus software, wrote Hyun Choi of Microsoft's Malware Protection Center, on Sunday.

One of the malware programs, called Vobfus, was detected in September 2009. It is known as a downloader, or a program that downloads other pieces of code.

Once Vobfus infects a computer, it downloads from a remote command-and-control server a program called Beebone, which is another kind of downloader that installs other malicious programs on a computer. The two work together, downloading variants of the other that are not immediately detected by antivirus products, Choi wrote.

"This cyclical relationship between Beebone and Vobfus downloading each other is the reason why Vobfus may seem so resilient to antivirus products," Choi wrote. Updated antivirus products may detect one variant present on the system; however, newer downloaded variants may not be detected immediately."

Other malware programs have been known to update themselves once a computer is infected. But if the malware is detected and removed, the targeted computer would have to be infected again by an attacker. The approach of Vobfus and Beebone makes it more likely the computer will remain infected.

Vobfus is also a worm that copies itself to removable drives. It uses the autorun function that, if enabled on a computer, causes Vobfus to automatically run and infect Windows computers.

"In the wild, we have observed that Vobfus maintains a very successful removable-drive infection rate," Choi wrote.

Send news tips and comments to jeremy_kirk@idg.com. Follow me on Twitter: @jeremy_kirk

Join the PC World newsletter!

Error: Please check your email address.

Tags securityMicrosoftmalware

Struggling for Christmas presents this year? Check out our Christmas Gift Guide for some top tech suggestions and more.

Keep up with the latest tech news, reviews and previews by subscribing to the Good Gear Guide newsletter.

Jeremy Kirk

IDG News Service

Most Popular Reviews

Follow Us

Best Deals on GoodGearGuide

Shopping.com

Latest News Articles

Resources

GGG Evaluation Team

Kathy Cassidy

STYLISTIC Q702

First impression on unpacking the Q702 test unit was the solid feel and clean, minimalist styling.

Anthony Grifoni

STYLISTIC Q572

For work use, Microsoft Word and Excel programs pre-installed on the device are adequate for preparing short documents.

Steph Mundell

LIFEBOOK UH574

The Fujitsu LifeBook UH574 allowed for great mobility without being obnoxiously heavy or clunky. Its twelve hours of battery life did not disappoint.

Andrew Mitsi

STYLISTIC Q702

The screen was particularly good. It is bright and visible from most angles, however heat is an issue, particularly around the Windows button on the front, and on the back where the battery housing is located.

Simon Harriott

STYLISTIC Q702

My first impression after unboxing the Q702 is that it is a nice looking unit. Styling is somewhat minimalist but very effective. The tablet part, once detached, has a nice weight, and no buttons or switches are located in awkward or intrusive positions.

Latest Jobs

Shopping.com

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?