Malicious advertisements on major sites compromised many computers

New vulnerabilities in Flash combined with malicious ads are helping attackers

Attackers who have slipped malicious advertisements onto major websites over the last month have potentially compromised large numbers of computers.

Several security vendors have documented attacks involving malicious advertisements, which automatically redirect victims to other websites or pages that silently attack their computer and install malware.

"We certainly see malvertising on the rise," said Nick Bilogorskiy, head of security research at Cyphort, a security vendor in Santa Clara, California. "We see it is going to be a major channel of delivering malware this year."

For the second time in about a month, Cyphort found malicious advertisements popping up on major websites including the Huffington Post and the LA Weekly between Thursday and Monday. The attack is likely a continuation of the first one, Bilogorskiy said.

The malvertisements were distributed by Adtech.de, an AOL-owned online advertising company, and two other companies, adxpansion.com and Ad.directrev.com. The bad ads appear to have been removed from Adtech, Bilogorskiy said, who has been in touch with its security team. He couldn't reach the other two companies.

The malicious advertisements redirected users through several domains before finally dumping them on pages hosting an exploit kit, an attack tool that scans for software vulnerabilities. It appears this campaign uses the Sweet Orange exploit kit, Bilogorskiy said.

If a vulnerability is found, malware is automatically delivered, a dangerous type of attack known as a drive-by download. "It's the worst case," Bilogorskiy said.

The malware installed is called Kovter, which is used to fraudulently generate ad impressions.

It can be difficult for online advertising companies to keep bad ads out of their systems. The companies "are getting millions of ads submitted to them, and any one of them could be malware," Bilogorskiy said.

"They try their best to detect and filter, but it is challenging," he said.

Attackers, for example, may enable malicious payloads after their ads have been approved. Other times, they may only attack every 10th user. The ads, Bilogorskiy said, have to be repeatedly checked to ensure they're not malicious.

On Tuesday, Cisco's Talos security research group wrote it had analyzed another large malvertising campaign that uses the Angler exploit kit, a potent one known for its quick employment of the latest Flash vulnerabilities.

More than 1,800 legitimate domains were being used as part of that campaign, wrote Nick Biasini, a Cisco threat researcher. It appeared the attackers had gained control of the domains' accounts, many of which were registered through GoDaddy, he wrote.

The attackers created subdomains on those accounts. People who viewed a malicious ad were redirected to a newly-created subdomain, which then redirected to another subdomain that served up the exploit kit.

The attackers have created so many subdomains that one may only be used once to redirect, Biasini wrote. Since malicious domains are often quickly detected and blocked by security software, rotating them helps ensure an attack will be successful.

The Angler attacks kicked off after victims viewed malicious ads, he wrote.

On Monday, Trend Micro said it discovered a new zero-day in Adobe System's Flash software after analyzing malvertisement attacks involving Angler. The malvertisement had been seen on the popular website Dailymotion.

The Flash flaw, CVE-2015-0313, is the third one found in the application in a month. Adobe plans to fix it later this week.

Send news tips and comments to jeremy_kirk@idg.com. Follow me on Twitter: @jeremy_kirk

Join the newsletter!

Error: Please check your email address.
Rocket to Success - Your 10 Tips for Smarter ERP System Selection

Tags securityinternetmalwareadvertisingAOL.com

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

Jeremy Kirk

IDG News Service
Show Comments

Cool Tech

SanDisk MicroSDXC™ for Nintendo® Switch™

Learn more >

Breitling Superocean Heritage Chronographe 44

Learn more >

Toys for Boys

Family Friendly

Panasonic 4K UHD Blu-Ray Player and Full HD Recorder with Netflix - UBT1GL-K

Learn more >

Stocking Stuffer

Razer DeathAdder Expert Ergonomic Gaming Mouse

Learn more >

Christmas Gift Guide

Click for more ›

Most Popular Reviews

Latest Articles

Resources

PCW Evaluation Team

Edwina Hargreaves

WD My Cloud Home

I would recommend this device for families and small businesses who want one safe place to store all their important digital content and a way to easily share it with friends, family, business partners, or customers.

Walid Mikhael

Brother QL-820NWB Professional Label Printer

It’s easy to set up, it’s compact and quiet when printing and to top if off, the print quality is excellent. This is hands down the best printer I’ve used for printing labels.

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

Featured Content

Latest Jobs

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?