IE flaw exploited for MSN Messenger worm

A new worm that uses Microsoft's instant messenger application MSN Messenger to propagate has been spotted by several antivirus software vendors.

The worm arrives in an instant message that contains text telling the recipient to go to one of several Web sites. The text says either "URGENT -- go to (url) now," or "ATTeNT!oN -- go to (url) now." Clicking on the URL (Uniform Resource Locator) link in the message opens a Web page with malicious JavaScript code that sends instant messages advertising the Web page, or other Web pages with the code, to all the MSN Messenger users on the user's contacts list, Symantec and F-Secure said in advisories Thursday.

Dubbed "JS.Menger.Worm" by Symantec and "Coolnow" by F-Secure, the worm sends instant messages, but does no damage to a user's system, the antivirus software vendors said. F-Secure is trying to shut down the sites hosting the malicious code before it becomes very widespread, the company said.

The JavaScript code takes control of MSN Messenger by exploiting a known flaw in Microsoft's Internet Explorer (IE) Web browser. An example of how to stage such an attack was published last weekend by two European experts. That example was used to craft the worm, according to the experts.

"The worm is a modified version of our example code. We never intended for anybody to copy the code, although we kind of expected it would happen," said Thor Larholm, one of the two Europeans who demonstrated how specially crafted code on a Web page could take over MSN Messenger. "We published the example to put pressure on Microsoft to patch vulnerabilities that they are fully aware of."

Microsoft on Monday released a bundle of patches for IE that fixes the flaw used by the MSN Messenger worm, Larholm and the antivirus software vendors said.

Still, a PC with IE is all but secure, according to Larholm.

"The patch doesn't fix all the problems in IE. It fixes a lot, Microsoft deserves kudos for that, but there are still publicly known vulnerabilities, some two months old, that allow an attacker to read any local file and execute arbitrary commands on a user's system," Larholm said. The Danish Internet programmer maintains a list of unplugged holes on his Web site (http://jscript.dk/unpatched/).

Both Symantec and F-Secure have updated their antivirus products so they can detect the worm. No one at Microsoft was immediately available to comment.

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.
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?