Researchers 'poison' Storm botnet

First publicly released research attempting to actively disrupt a peer-to-peer botnet unveiled in Germany

A group of German researchers has unveiled the first publicly released research attempting to actively disrupt a peer-to-peer botnet - using as their case study the notorious Storm worm.

The researchers were able not only to infiltrate Storm, gaining in the process the most precise estimates of its size to date, but also had success in disrupting its communications through a "poisoning" technique, according to the study.

The study, "Measurements and Mitigation of Peer-to-Peer-based Botnets," was authored by five researchers working with the University of Mannheim and Institut Eurecom, and was presented at the Usenix Workshop on Large-Scale Exploits and Emergent Threats (LEET) earlier this month in San Francisco.

Botnets have become among the most pressing threats on the internet, accounting for most spam and capable of directing large-scale denial-of-service and other categories of attacks.

Most recently, botnets such as that created by the Storm worm have begun using peer-to-peer techniques for communications, eliminating the need for a central control server and making them far more difficult to shut down.

By taking a more active approach, the researchers found a way to "poison" the communications of the Storm bots, effectively disrupting them.

"Our strategy can be used as a way to disable the communication within the Storm botnet to a large extent," they wrote in the study. "As a side effect, we are able to estimate the size of the Storm botnet, in general a hard task."

Previous research has been based on passive techniques such as observing network events such as the number of spam emails thought to have originated from a particular botnet, the researchers said.

They said the new study is the first to use active techniques, crawling the P2P network, keeping track of all peers and distinguishing infected peers from benign ones based on behavior.

Crawling the "Stormnet" every 30 minutes from the beginning of December 2007 to the beginning of February 2008, the researchers found between 5,000 and 40,000 peers online at any given time, with a sharp increase in bots during the Christmas and New Years Eve periods.

The bots were located in more than 200 countries, with the biggest proportion in the US, at 23 percent.

The "poisoning" technique involves the keys used by Storm bots to establish communication. The researchers published a large amount of false content for particular keys.

"Our experiments show that by polluting all those hashes that we identified to be storm hashes, we can disrupt the communication of the botnet," the researchers wrote.

Another technique, called a "sybil" or "eclipse" attack, aiming to separate a part of the P2P network from the rest, proved ineffective.

Active interference with a botnet may carry serious legal consequences for researchers, since the botnet hosts are effectively computer systems belonging to third parties, who ordinarily are unaware that their systems are being misused.

In part because of this factor, previous research has focused on passive techniques for identifying the size and control structure of a botnet, leaving law enforcement authorities to take action, the researchers acknowledged.

The researchers said future efforts will focus on analyzing a second tier of systems that issue the actual commands, which might allow the identification of the operators of the Storm worm.

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

Matthew Broersma

Techworld.com
Comments are now closed.

Latest News Articles

Most Popular Articles

Follow Us

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.

Resources

Best Deals on GoodGearGuide

Compare & Save

Deals powered by WhistleOut
WhistleOut

Latest Jobs

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?