Java-based Web attack installs hard-to-detect malware in RAM

Kaspersky Lab researchers investigated a drive-by download attack that installs malware which only lives in the computer's memory

A hard-to-detect piece of malware that doesn't create any files on the affected systems was dropped onto the computers of visitors to popular news sites in Russia in a drive-by download attack, according to security researchers from antivirus firm Kaspersky Lab.

Drive-by download attacks are one of the primary methods of distributing malware over the Web. They usually exploit vulnerabilities in outdated software products to infect computers without requiring user interaction.

Kaspersky Lab researchers recently investigated such an attack on visitors to www.ria.ru, a website that belongs to the Russian RIA Novosti news agency, and www.gazeta.ru, a popular Russian-language online newspaper.

The attack code loaded an exploit for a known Java vulnerability (CVE-2011-3544), but it wasn't hosted on the affected websites themselves. Instead, it was served to their visitors through banners displayed by a third-party advertising service called AdFox.

What's interesting about this particular attack is the type of malware that was installed in cases of successful exploitation: one that only lives in the computer's memory.

"The operation of such an exploit involves saving a malicious file, usually a dropper or downloader, on the hard drive," said Kaspersky Lab expert Sergey Golovanov, in a blog post on Friday. "However, in this case we were in for a surprise: No new files appeared on the hard drive."

The Java exploit's payload consisted of a rogue DLL (dynamic-link library) that was loaded and attached on the fly to the legitimate Java process. This type of malware is rare, because it dies when the system is rebooted and the memory is cleared.

However, this wasn't a problem for the cybercriminals behind this particular attack, because of the very high probability that most victims would revisit the infected news websites, Golovanov said.

The malicious DLL loaded into memory acted as a bot, sending data to and receiving instructions from a command and control server over HTTP. In some cases, the instructions given out by attackers were to install an online banking Trojan horse on the compromised computers.

"This attack targeted Russian users. However, we cannot rule out that the same exploit and the same fileless bot will be used against people in other parts of the world: They can be distributed via similar banner or teaser networks in other countries," Golovanov said.

The best protection against this type of attack is to keep the installed software on computers up to date, especially browsers and their plug-ins. In case exploits that target previously unknown vulnerabilities are used, it's best to have an antivirus product running that is capable of scanning Web traffic and detecting attack code generically.

It's ideal to stop the infection in its early stages, because once this type of "fileless" malware gets loaded into memory and attaches itself to a trusted process, it's much harder to detect by antivirus programs, Golovanov said.

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.
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

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?