Facebook worm spreads with a lurid lure

Facebook said the problem only affected a small number of users and disputes it is a worm

Some Facebook users have been infected with a worm after clicking on an image of a scantily clad woman, which then redirects the victims to a pornography site, according to security researchers.

The worm posts an image on a victim's Facebook Wall with a photo of a woman in a bikini and the message "click 'da button, baby." Wall posts are viewable by a Facebook user's friends.

If a friend clicks on the image and is logged into Facebook, the image is then is posted to their own Wall.

Their Web browser will then open a Web page with a larger version of the same image. A further click on "da button" redirects the friend to a pornography site, according to Roger Thompson chief research officer for antivirus vendor AVG Technologies.

Thompson posted a video of the attack on his blog.

The creators of the worm are likely making money by driving referrals to the pornography site, said Nick FitzGerald, a threat researcher for security vendor AVG.

Researchers aren't quite sure exactly how the worm works but believe it may be a cross-site request forgery attack (CSRF) or a clickjacking attack or a mix of both.

A CSRF attack occurs when a victim's credentials are used to perform some action but without their knowledge. In this case, the attacker fraudulently posts the image to the victim's Facebook Wall, piggybacking on the fact the victim is logged into their account.

Another possibility is clickjacking, where attackers use special Web programming to trick victims into clicking Web buttons without realizing it.

Clickjacking is possible due to a fundamental design feature in HTML that allows Web sites to embed content from other Web pages. Web browsers are vulnerable to clickjacking attacks, although browser makers have worked to shore up defenses against them.

Facebook classifies the attack as clickjacking, an attack that is "not specific to Facebook," according to a written statement. Facebook also said the attack was not a worm.

"We've taken action to block the URL (Uniform Resource Locator) associated with this site, and we're cleaning up the relatively few cases where it was posted," the statement said. "Overall, an extremely small percentage of users were affected."

If the worm does spread through a clickjacking attack, "it may be difficult for Facebook to fix reliably," FitzGerald said. "Regardless, it is a worm."

Facebook warned users not to click on suspicious links. However, in this case, the link doesn't stand out as necessarily suspicious given the variety of Wall postings, graphics and applications that appear all over the popular social-networking site.

In fact, one security researcher inadvertently reposted the suspect graphic before realizing something wasn't right.

"This shows that even experts can become complacent and trust systems when they really shouldn't," wrote Gadi Evron, an independent security researcher, on Dark Reading's blog.

Join the newsletter!

Error: Please check your email address.
Rocket to Success - Your 10 Tips for Smarter ERP System Selection

Tags wormAVGsocial networkingFacebook

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

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.

Matthew Stivala

HP OfficeJet 250 Mobile Printer

The HP OfficeJet 250 Mobile Printer is a great device that fits perfectly into my fast paced and mobile lifestyle. My first impression of the printer itself was how incredibly compact and sleek the device was.

Featured Content

Latest Jobs

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?