Hackers exploit latest IE zero-day with drive-by attacks

Researchers expect attacks to explode once exploit code goes public

Hackers are exploiting the just-disclosed unpatched bug in Internet Explorer (IE) to launch drive-by attacks from malicious Web sites, security researchers said today.

"This attack appears to be rather targeted at the moment, but as with other unpatched vulnerabilities in the past, this has the potential to explode now that the word is getting out," said Craig Schmugar, a threat researcher at McAfee, in a blog post today.

Attacks are launched from Web sites in a classic drive-by fashion, said Schmugar and others. "Visiting the page is enough to get infected," Schmugar said.

Symantec also confirmed that it has spotted in-the-wild attacks exploiting the critical vulnerability in IE6 and IE7 that Microsoft acknowledged yesterday. "We're still seeing just limited attacks," said Ben Greenbaum, a senior research manager with Symantec's security response team. "The exploit is carried out simply by visiting a Web page hosting the vulnerability," he continued. "When the browser opens the page, the exploit causes the user's computer to download and execute another piece of malware."

Most of the malware downloaded and installed on the victimized PC consists of backdoors that let hackers install and run even more attack code. Among the malware is a .dll that's injected into IE to provide additional remote access to the machine, Schmugar said.

"It started out as limited and targeted, but now, with the drive-by attacks, it's no longer only a targeted attack," said Schmugar in an interview today.

Tuesday, Microsoft warned users of IE6 and IE7 that attackers were using an unpatched vulnerability in their browsers, but as is its practice, did not publish technical details of the bug.

Nor did Microsoft spell out a patching timetable, or promise that it would issue a fix before the next scheduled Patch Tuesday on April 13. Instead, it recommended that users modify access to the "iepeers.dll," disable scripting, and/or enable DEP (data execution prevention).

According to Vupen Security , the bug is a "user-after-free" memory error in how iepeers.dll handles certain data. "User-after-free" refers to an attempt to reuse memory space after it has been freed, said Andrew Storms, director of security operations at nCircle Network Security, in an instant message interview.

Neither Symantec nor McAfee have yet found evidence that the attack code has been widely distributed via hacker forums or posted more prominently on the Internet. When that happens, Schmugar said he expects attacks to quickly increase.

Microsoft may be forced to react with an emergency update if that happens, Greenbaum said. "It's possible Microsoft may consider an out-of-band patch for this issue," he said.

Symantec notified Microsoft of its discovery of the drive-by attacks a few hours before the latter issued its advisory, Greenbaum said. "The timeline, however, makes us think that they already knew about the issue and were planning on posting the advisory very soon anyway," he said.

Both Symantec and McAfee have created and distributed signatures that detect and block the installation of the malware that the drive-by exploit tries to inject into PCs.

Tuesday's advisory was the second in the last 60 days from Microsoft warning of ongoing attacks against an unpatched IE vulnerability. In mid-January, Microsoft said that a flaw in its browser had been used to attack several companies' networks, including Google 's and Adobe's. Microsoft patched that vulnerability, and seven others, later in the month when it shipped an out-of-band update .

Users able to can also upgrade Internet Explorer to IE8 , which does not contain the bug and so is immune from attack.

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 MicrosoftInternet Explorerexploits and vulnerabilitieszero day exploit

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

Computerworld Staff

Computerworld (US)
Show Comments

Cool Tech

Toys for Boys

Family Friendly

Stocking Stuffer

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

Aysha Strobbe

Microsoft Office 365/HP Spectre x360

Microsoft Office continues to make a student’s life that little bit easier by offering reliable, easy to use, time-saving functionality, while continuing to develop new features that further enhance what is already a formidable collection of applications

Michael Hargreaves

Microsoft Office 365/Dell XPS 15 2-in-1

I’d recommend a Dell XPS 15 2-in-1 and the new Windows 10 to anyone who needs to get serious work done (before you kick back on your couch with your favourite Netflix show.)

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.

Featured Content

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?