Cambridge professor warns of Skype botnet threat

Voice-over-IP applications could be used to cloak networks of zombies, used to launch denial of service attacks, a professor at the U.K.'s Cambridge University has warned.

Armies of ordinary PCs that have been infected by a virus and put under malicious control, known as "botnets," could be controlled and orchestrated by messages hidden in VoIP traffic generated by programs such as Skype, warned Jon Crowcroft, Marconi professor of communications systems at Cambridge University.

Denial-of-service (DoS) attacks are usually shut down by tracing control messages, normally sent by chat and IM programs. "If someone were to use a VoIP overlay as a control tool for attacks, it would be much harder to find affected computers and almost impossible to trace the criminals behind the operation," said Crowcroft, who revealed the technique at the Communications Research Network (CRN), a networking think-tank funded by the Cambridge-MIT Institute, a joint venture between the two universities.

"It would be irresponsible to build something that could go out and be used," said Crowcroft, but he nevertheless built a demonstration system. "It was write-once, tear-up code. But it was very easy to do - unfortunately."

Although the attack has not been detected in actual use yet, Crowcroft warns it is only a matter of time. The CRN's working group on Internet Security has raised the issue with VoIP providers, before making the issue public.

"There isn't a protocol you can't use as a covert signalling channel," responded Kurt Sauer, director of security operations at Skype. "Some large commercial groupware products have encrypted XML streams - they may not be quite as good at firewall traversal, but that's still an opaque data stream."

The attack will add to the unease enterprise IT staff already feel about applications, particularly the very popular Skype service. Some IT managers do not want uncontrolled traffic punching holes in their firewalls, and using bandwidth, and security vendors have launched specific products to block Skype.

Crowcroft would like Skype to publish its routing specifications, so IT managers can work better with the application, tracking it and checking its behaviour. "Skype's routing specification is proprietary," he said. "There are a whole bunch of reasons why obfuscation is not helpful in the long run."

Although Skype still wants its proprietary edge, the issue is up for discussion: "The people who own networks and systems have a right to manage as they see fit," said Sauer. "To the extent that we make it difficult to do that, want to address that in our products."

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.

Peter Judge

Techworld.com
Show Comments

Cool Tech

SanDisk MicroSDXC™ for Nintendo® Switch™

Learn more >

Breitling Superocean Heritage Chronographe 44

Learn more >

Toys for Boys

Family Friendly

Panasonic 4K UHD Blu-Ray Player and Full HD Recorder with Netflix - UBT1GL-K

Learn more >

Stocking Stuffer

Razer DeathAdder Expert Ergonomic Gaming Mouse

Learn more >

Christmas Gift Guide

Click for more ›

Most Popular Reviews

Latest Articles

Resources

PCW Evaluation Team

Edwina Hargreaves

WD My Cloud Home

I would recommend this device for families and small businesses who want one safe place to store all their important digital content and a way to easily share it with friends, family, business partners, or customers.

Walid Mikhael

Brother QL-820NWB Professional Label Printer

It’s easy to set up, it’s compact and quiet when printing and to top if off, the print quality is excellent. This is hands down the best printer I’ve used for printing labels.

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

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?