Tricky new malware challenges vendors

A new piece of malware is using advanced techniques to foil antivirus software

A tricky malicious program has become more prevalent in spam, but experts don't know what its creators plan to do with it.

Many vendors are rating the malware -- called "Warezov," "Stration" and "Stratio" -- as a low risk. But they also say that it is tricky to deal with.

The malware is a mass-mailing worm that affects machines running Microsoft's Windows OS. When the malware infects a computer -- usually after the user has opened an attachment containing the worm in a spam e-mail -- it sends itself out again to other e-mail addresses found on the computer. The code is then capable of downloading new versions of itself as frequently as every 30 minutes from a batch of websites, said Mikko Hypponen, chief research officer at F-Secure, a security company in Helsinki.

Those new versions are created by a program on a server controlled by the hacker, Hypponen said.

In the past, malware has been known to create variations of itself, but the code to create those variations was contained inside the malware. So when a sample was obtained, security analysts could study it and identify potential new versions, he said.

Now, the hacker's program is compiling the code and rapidly churning out new versions, but analysts don't know how the new code is generated.

That characteristic is a headache for security software firms that issue special updates to their software to detect the malware. F-Secure alone has issued at least 150 signatures for the malware.

"It gets very complex to detect an attack like that because the code keeps changing," Hypponen said.

Security firm Sophos has detected some 300 versions of the malware. For October, the malware was one of the most common pieces of malicious code found in spam messages, said Carole Theriault, senior security consultant with Sophos.

Since infected computers look to other domains to receive updated code, F-Secure has worked with ISPs (Internet service providers) to shut down domains hosting the new variants. So far, nine of 10 domains have been shut down, Hypponen said.

Oddly, the malware doesn't appear to do anything yet on the victim's computers. It's estimated up to a few hundred thousand computers are infected, a sizable number but not quite on the scale of large malware problems from a few years ago, Hypponen said.

A hacker could be waiting to harness enough infected computers to start a denial-of-service attack or send spam or rent out the network to a spammer, Hypponen said.

"We hope to one day find out why they are doing this," Hypponen said. "We hope it's nothing too bad."

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.

Jeremy Kirk

IDG News Service
Show Comments

Most Popular Reviews

Latest Articles

Resources

PCW Evaluation Team

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

David Coyle

Brother PocketJet PJ-773 A4 Portable Thermal Printer

I rate the printer as a 5 out of 5 stars as it has been able to fit seamlessly into my busy and mobile lifestyle.

Kurt Hegetschweiler

Brother PocketJet PJ-773 A4 Portable Thermal Printer

It’s perfect for mobile workers. Just take it out — it’s small enough to sit anywhere — turn it on, load a sheet of paper, and start printing.

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?