Feeds

Google's DoubleClick spreads malicious ads (again)

Lingering threat still not contained

Using blade systems to cut costs and sharpen efficiencies

Google's DoubleClick ad network has once again been caught distributing malicious banner displays, this time on the home page of eWeek.

Unsuspecting end users who browse the Ziff Davis Enterprise Holdings-owned site were presented with malvertisements with invisible iframes that redirect them to attack websites, according to researchers at Websense. The redirects use one of two methods to infect users with malware, including rogue anti-virus software.

In one case, a PDF with heavily obscured javascript shunted victims to a subdomain at inside.com. (The PDF in not related to the zero-day vulnerability currently menacing Adobe Reader, Dan Hubbard, vice president of security research at Websense, says). In other scenarios, a generic index.php file did the bidding.

Once users were redirected, the site dropped a series of malicious files, including one named winratit.exe, into a user's temporary files folder and then prompted them to be automatically called the next time the machine rebooted. The result was the installation of Anti-Virus-1. It invites users to divulge their payment details and also alters their host file to make it hard to disinfect the machine.

The scourge of malvertisements has been a lingering threat over the past few years, and as the world's biggest ad network, DoubleClick has repeatedly been caught playing an unwitting role. Booby-trapped banner ads are the perfect vector because they hit users while visiting trusted sites, so their guard is down.

Catching the tainted banners has been challenging for DoubleClick and its competitors because the perpetrators often go to great lengths to conceal their activities. Miscreants often set up fictitious advertising agencies that appear to be legitimate. They also have the ability to turn the attacks on and off at the drop of a dime to evade sensors seeking out the malicious ads.

Given DoubleClick's tremendous reach, it's possible the rogue ads have shown up on websites other than eWeek, Hubbard said.

A Google spokesman said: "Our scanners have found a few instances of these malware ads in the DoubleClick network. As such, we've added these domains to our malware list and are in the process of removing any offending ads from our ad network."

He declined to say how long the attacks had been active, how many websites they affected or how the attackers were able to bypass Doubleclick's defenses. ®

Boost IT visibility and business value

More from The Register

next story
Secure microkernel that uses maths to be 'bug free' goes open source
Hacker-repelling, drone-protecting code will soon be yours to tweak as you see fit
14 antivirus apps found to have security problems
Vendors just don't care, says researcher, after finding basic boo-boos in security software
How long is too long to wait for a security fix?
Synology finally patches OpenSSL bugs in Trevor's NAS
Israel's Iron Dome missile tech stolen by Chinese hackers
Corporate raiders Comment Crew fingered for attacks
Roll out the welcome mat to hackers and crackers
Security chap pens guide to bug bounty programs that won't fail like Yahoo!'s
HIDDEN packet sniffer spy tech in MILLIONS of iPhones, iPads – expert
Don't panic though – Apple's backdoor is not wide open to all, guru tells us
Researcher sat on critical IE bugs for THREE YEARS
VUPEN waited for Pwn2Own cash while IE's sandbox leaked
Four fake Google haxbots hit YOUR WEBSITE every day
Goog the perfect ruse to slip into SEO orfice
prev story

Whitepapers

Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
Consolidation: The Foundation for IT Business Transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.
Application security programs and practises
Follow a few strategies and your organization can gain the full benefits of open source and the cloud without compromising the security of your applications.
How modern custom applications can spur business growth
Learn how to create, deploy and manage custom applications without consuming or expanding the need for scarce, expensive IT resources.
Securing Web Applications Made Simple and Scalable
Learn how automated security testing can provide a simple and scalable way to protect your web applications.