Menu
Yahoo tackles large 'malvertising' campaign in its ad network

Yahoo tackles large 'malvertising' campaign in its ad network

Ads with malicious code may have appeared across Yahoo's sites

Yahoo Corporate building in the daytime

Yahoo Corporate building in the daytime

Yahoo said Monday it had removed malware from its advertising network, after malicious code there had gone undetected for at least six days.

Security researchers at Malwarebytes said they discovered malicious ads planted in Yahoo's network on Sunday and alerted Yahoo. The malware attack had been underway since last Tuesday, wrote Jerome Segura, a senior security researcher at Malwarebytes Labs.

The malware was found in Yahoo's ads network at ads.yahoo.com, which runs ads across Yahoo's sites like its finance, games and news portals, as well as Yahoo.com. Users may have come across the infected ads when visiting Yahoo's sites.

A Yahoo spokeswoman declined to say how many advertisers were affected.

The attack used a method known as malvertising, in which attackers dupe online publishers into running malicious ads. They look like any other ads and may not require any interaction from users to infect their machines. If a visitor comes across a malicious ad, it can cause their browser to redirect to another site that attacks their computer.

In Yahoo's case, Malwarebytes detected ransomware, which encrypts files on users' computers unless they pay money to the attackers. The malware had also targeted sites hosted by Microsoft's Azure cloud platform, Malwarebytes said.

It's not the first time Yahoo's system has been hit with malvertising. Last year, an aggressive campaign was discovered that affected visitors across Yahoo and AOL's sites.

Malvertising might be becoming more prevalent in general. Last week, security company Cyphort said 10 million people may have visited websites carrying malicious ads in the last 10 days alone.

Experts advise users to keep their operating systems, browsers and browser plug-ins up to date to avoid becoming infected by malvertising. Yahoo visitors can also run a scan with their antivirus or anti-malware software, Malwarebytes said.

Zach Miners covers social networking, search and general technology news for IDG News Service. Follow Zach on Twitter at @zachminers. Zach's e-mail address is zach_miners@idg.com

Follow Us

Join the New Zealand Reseller News newsletter!

Error: Please check your email address.

Tags advertisingInternet-based applications and servicesYahoosecurityMalwarebytesinternetmalware

Slideshows

Meet the leading HP partners in New Zealand...

Meet the leading HP partners in New Zealand...

HP has recognised its top performing partners in New Zealand at the second annual 2016 HP Partner Awards, held at a glittering bash in Auckland. The HP Partner Awards recognises and celebrates excellence, growth, consistency and engagement of its top partners. This year also saw the addition of several new categories, resulting in 11 companies winning across 11 award categories.

Meet the leading HP partners in New Zealand...
Channel comes together as Ingram Micro Showcase hits Auckland

Channel comes together as Ingram Micro Showcase hits Auckland

Ingram Micro outlined its core focuses for 2017 at Showcase in Auckland, bringing together the channel for a day of engaging keynotes, compelling breakout sessions and new technologies.

Channel comes together as Ingram Micro Showcase hits Auckland
Show Comments