Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

A New Way to Protect Computer Networks from Internet Worms

06.06.2008
Scientists may have found a new way to combat the most dangerous form of computer virus.

The method automatically detects within minutes when an Internet worm has infected a computer network. Network administrators can then isolate infected machines and hold them in quarantine for repairs.

Ness Shroff, Ohio Eminent Scholar in Networking and Communications at Ohio State University, and his colleagues describe their strategy in the current issue of IEEE Transactions on Dependable and Secure Computing. They discovered how to contain the most virulent kind of worm: the kind that scans the Internet randomly, looking for vulnerable hosts to infect.

"These worms spread very quickly," Shroff said. "They flood the Net with junk traffic, and at their most benign, they overload computer networks and shut them down."

Code Red was a random scanning worm, and it caused $2.6 billion in lost productivity to businesses worldwide in 2001. Even worse, Shroff said, the worm blocked network traffic to important physical facilities such as subway stations and 911 call centers.

"Code Red infected more than 350,000 machines in less than 14 hours. We wanted to find a way to catch infections in their earliest stages, before they get that far," Shroff said.

The key, they found, is for software to monitor the number of scans that machines on a network send out. When a machine starts sending out too many scans -- a sign that it has been infected -- administrators should take it off line and check it for viruses.

The strategy sounds straightforward enough. A scan is just a search for Internet addresses -- what we do every time we use search engines such as Google. The difference is, a virus sends out many scans to many different destinations in a very short period of time, as it searches for machines to infect.

"The difficulty was figuring out how many scans were too many," Shroff said. "How many could you allow before an infection would spread wildly? You want to make sure the number is small to contain the infection. But if you make it too small, you'll interfere with normal network traffic."

"It turns out that you can allow quite a large number of scans, and you'll still catch the worm."

Shroff was working at Purdue University in 2006 when doctoral student Sarah Sellke suggested making a mathematical model of the early stages of worm growth. With Saurabh Bagchi, assistant professor of electrical and computer engineering at Purdue, they developed a model that calculated the probability that a virus would spread, depending on the maximum number of scans allowed before a machine was taken off line.

In simulations, they pitted their model against the Code Red worm, as well as the SQL Slammer worm of 2003. They simulated how far the virus would spread, depending on how many networks on the Internet were using the same containment strategy: quarantine any machine that sends out more than 10,000 scans.

They chose 10,000 because it is well above the number of scans that a typical computer network would send out in a month.

"An infected machine would reach this value very quickly, while a regular machine would not," Shroff explained. "A worm has to hit so many IP addresses so quickly in order to survive."

In the simulations pitted against the Code Red worm, they were able to prevent the spread of the infection to less than 150 hosts on the whole Internet, 95 percent of the time.

A variant of Code Red worm (Code Red II) scans the local network more efficiently, and finds vulnerable targets much faster. Their method was effective in containing such worms. In the simulations, they were able to trap the worm in its original network -- the one that would have started the outbreak -- 77 percent of the time.

Anywhere from 10 to 20 percent of the time, it spread to one other network, but no further. The remaining 3 to 13 percent of the time, it escaped to more networks, but the infection was slowed.

In all cases, there was a dramatic decrease in the spread of the worm within the first hour.

To use this strategy, network administrators would have to install software to monitor the number of scans on their networks, and would have to allow for some downtime among computers when they initiate a quarantine.

According to Shroff, that wouldn't be a problem for most organizations. Very small businesses -- ones with only a few servers -- may have more difficulty taking their machines off line.

"Unfortunately there is no complete foolproof solution," Shroff said. "You just keep trying to come up with techniques that limit a virus's ability to do harm."

He and his colleagues are working on adapting their strategy to stop targeted Internet worms -- ones that have been designed specifically to attack certain vulnerable IP addresses.

This work was supported by a grant from the National Science Foundation, and Sarah Sellke's NSF Graduate Fellowship.

Contact: Ness Shroff, (614) 247-6554; Shroff.11@osu.edu

Pam Frost Gorder | newswise
Further information:
http://www.osu.edu

More articles from Information Technology:

nachricht Defining the backbone of future mobile internet access
21.07.2017 | IHP - Leibniz-Institut für innovative Mikroelektronik

nachricht Researchers create new technique for manipulating polarization of terahertz radiation
20.07.2017 | Brown University

All articles from Information Technology >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

Im Focus: On the way to a biological alternative

A bacterial enzyme enables reactions that open up alternatives to key industrial chemical processes

The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....

Im Focus: The 1 trillion tonne iceberg

Larsen C Ice Shelf rift finally breaks through

A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...

Im Focus: Laser-cooled ions contribute to better understanding of friction

Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision

Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

 
Latest News

NASA looks to solar eclipse to help understand Earth's energy system

21.07.2017 | Earth Sciences

Stanford researchers develop a new type of soft, growing robot

21.07.2017 | Power and Electrical Engineering

Vortex photons from electrons in circular motion

21.07.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>