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!

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 internetmalwareadvertisingAOL.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

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

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.

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.

Featured Content

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?