Reader X spoils new PDF attack

But researchers are unsure whether Adobe's new sandbox helped block attack

Adobe's Reader X, last year's upgrade that features a "sandbox" designed to protect users from PDF exploits, stymied a recent attack campaign, researchers said Thursday.

But they're not sure why.

"I don't want to take anything away from Adobe -- after all, a win is a win -- but this particular exploit appears to be designed with previous versions of Reader in mind," said Chris Greamo, who heads the research lab at security company Invincea of Fairfax, Va. "What appears to have happened is that the exploit breaks, but we don't have a good sense if the sandbox was able to contain it."

Meanwhile, engineers at U.K.-based Sophos poked into the malware -- a malicious PDF document that's attached to spam -- and found that Reader X stops its execution. The same malware, which first was noticed by security firms last October, runs correctly when aimed at Adobe Reader 8, however.

The malformed PDF tries to exploit an already-patched vulnerability in older versions of Reader, said Chet Wisniewski, a senior security adviser with the antivirus company.

Like Greamo, Wisniewski wasn't able to definitively credit Reader X's sandbox for blocking the attack. "Was it the sandbox or that the malware was designed for Reader 8 and 9, not Reader X? I have a hunch it was both, really," Wisniewski said.

It's not unusual for malware to fail when run on, say, a different edition of Windows than what it was meant to attack, or to crash when encountering a newer version of the target application, even if the security vulnerability still exists in the update.

"[This malware] wouldn't have worked in any case, because the flaw it exploits only exists in older versions of Reader," Wisniewski said. "But even if it had, considering what the exploit had to do, the sandbox in Reader X would have provided protection."

At a minimum, Reader X is a win for Adobe, Wisniewski continued, because that version had eliminated the flaw.

Adobe said it had reached out to Sophos for more details about the malware to determine what vulnerability was targeted, and couldn't confirm that Reader X's sandbox had played a part.

"However, based on the description of the exploit, specifically that it attempts to download and run malicious code, we know the sandbox design seeks to prevent this type of action from happening, even if the vulnerability were present in the Adobe Reader X code base," said an Adobe spokeswoman in an e-mail reply to questions.

The spokeswoman added that no vulnerabilities that could be used to escape the sandbox have been reported to Adobe since Reader X debuted last November . "Nor have we seen any public discussion of sandbox-breaking exploits," she said.

That's good news for Adobe, which even before Reader X's launch had argued that security researchers would be looking for bugs in its sandbox. "Everyone will want bragging rights to be the first to come up with a working exploit of the sandbox," said Brad Arkin, Adobe's director of security and privacy, in an October 2010 interview .

Reader X's sandbox is based on technologies used by Google and Microsoft. The former sandboxes its Chrome browser, for example, while the latter uses similar defenses to protect Internet Explorer and Office 2010 on Windows.

Adobe also claimed that a recently-addressed bug in Chrome that lets attackers escape the browser's sandbox was not present in Reader X's sandbox code.

Google patched that bug, the first to earn the reporting researcher the company's top bug bounty of $3,133 , three weeks ago.

Also on Thursday, Adobe alerted customers that it would ship its next quarterly security update for Reader on Tuesday, Feb. 8.

Next week's Reader update will patch the Windows and Mac versions, including Reader X.

Sophos' Wisniewski urged Windows users to upgrade as soon as possible to take advantage of the sandbox defense. "Reader X is the most secure version of the program, and everyone should be using it," he said.

Gregg Keizer covers Microsoft, security issues, Apple, Web browsers and general technology breaking news for Computerworld. Follow Gregg on Twitter at @gkeizer or subscribe to Gregg's RSS feed . His e-mail address is gkeizer@computerworld.com .

Read more about security in Computerworld's Security Topic Center.

Join the newsletter!

Or

Sign up to gain exclusive access to email subscriptions, event invitations, competitions, giveaways, and much more.

Membership is free, and your security and privacy remain protected. View our privacy policy before signing up.

Error: Please check your email address.

Tags sophos

Keep up with the latest tech news, reviews and previews by subscribing to the Good Gear Guide newsletter.
Gregg Keizer

Gregg Keizer

Computerworld (US)
Show Comments

Cool Tech

Toys for Boys

Family Friendly

Stocking Stuffer

Logitech Ultimate Ears Wonderboom Bluetooth Speaker

Learn more >

SmartLens - Clip on Phone Camera Lens Set of 3

Learn more >

Christmas Gift Guide

Click for more ›

Brand Post

Most Popular Reviews

Latest Articles

Resources

PCW Evaluation Team

Maryellen Rose George

Brother PT-P750W

It’s useful for office tasks as well as pragmatic labelling of equipment and storage – just don’t get too excited and label everything in sight!

Cathy Giles

Brother MFC-L8900CDW

The Brother MFC-L8900CDW is an absolute stand out. I struggle to fault it.

Luke Hill

MSI GT75 TITAN

I need power and lots of it. As a Front End Web developer anything less just won’t cut it which is why the MSI GT75 is an outstanding laptop for me. It’s a sleek and futuristic looking, high quality, beast that has a touch of sci-fi flare about it.

Emily Tyson

MSI GE63 Raider

If you’re looking to invest in your next work horse laptop for work or home use, you can’t go wrong with the MSI GE63.

Laura Johnston

MSI GS65 Stealth Thin

If you can afford the price tag, it is well worth the money. It out performs any other laptop I have tried for gaming, and the transportable design and incredible display also make it ideal for work.

Andrew Teoh

Brother MFC-L9570CDW Multifunction Printer

Touch screen visibility and operation was great and easy to navigate. Each menu and sub-menu was in an understandable order and category

Featured Content

Product Launch Showcase

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?