Unpatched Java vulnerability exploited to infect Macs with Flashback malware

The Flashback.K variant is distributed via exploits for a known Java vulnerability that Apple has yet to patch

A Java vulnerability that hasn't yet been patched by Apple is being exploited by cybercriminals to infect Mac computers with a new variant of the Flashback malware, according to security researchers from antivirus firm F-Secure.

Flashback is a computer Trojan horse for Mac OS that first appeared in September 2011. The first variant was distributed as a fake Flash Player installer, but the malware has been changed significantly since then, both in terms of functionality and distribution methods.

Back in February, several antivirus companies reported that a new Flashback version was being distributed through Java exploits, which meant that the infection process no longer required user interaction.

The Java vulnerabilities targeted by the February exploits dated back to 2009 and 2011, so users with up-to-date Java installations were protected.

However, that's no longer the case with the latest variant of the malware, Flashback.K, which is being distributed by exploiting an unpatched Java vulnerability, security researchers from F-Secure said in a blog post Monday.

Oracle released a fix for the targeted vulnerability, which is identified as CVE-2012-0507, back in February and it was included in an update for the Windows version of Java.

However, since Apple distributes a self-compiled version of Java for Macs, it ports Oracle's patches to it according to its own schedule, which can be months behind the one for Java on Windows.

Security experts have long warned that this delay in delivering Java patches on Mac OS could be used by malware writers to their advantage, and the new Flashback.K malware confirms that they were right.

After being dropped and executed on the system via the CVE-2012-0507 exploit, the new Trojan horse prompts a dialog window that asks the user for their administrative password.

Regardless of whether the user inputs the password or not, the malware still infects the system, F-Secure said in its description of the malware. The Trojan's purpose is to inject itself into the Safari process and modify the contents of certain Web pages.

There are rumors that a new exploit for a different unpatched Java vulnerability is currently being sold on the underground market and could be used to target Mac users in a similar way in the future, the F-Secure researchers said.

"If you haven't already disabled your Java client, please do so before this thing really become an outbreak," they said. The antivirus company provides instructions on how to do this.

Apple stopped including Java by default in Mac OS X starting with version 10.7 (Lion). However, if Lion users encounter a Web page that requires Java, they are prompted to download and install the runtime and might later forget that they have it on their computers.

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.

Lucian Constantin

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?