Researchers at Malware Bytes confirmed that a malware attack was served via both Doubleclick and Zedo ad servers.

Attacks were noticed by visitors to sites such as last.fm, The Times of Israel and The Jerusalem Post. Ads being served through both Doubleclick and Zedo were involved in the malware distribution under the guise of unpatched Internet Explorer or Adobe Flash.  None of the sites themselves were infected, but the ads served on the sites were.

The attack was by the recently identified malware called Zemot – this particular attack first identified on August 30, 2014, meaning that some computers that weren’t up to date on their virus and malware protection were vulnerable to this particular attack.

Google did confirm that Doubleclick’s servers were affected in this “malvertising” attack.  According to the Verge, Google released a statement “our team is aware of this and has taken steps to shut this down.”

MediaPost spoke with Zedo about the malware.

Zedo has spent years trying to identify and stop this type of malware in advertisements, establishing processes and procedures. “Zedo is a leader in the anti-malvertising world, and always has been,” says a spokesperson for the company. “We immediately traced the problem and resolved it. Everything’s clear now. These incidents are not what we’d like to happen, and we address them as soon as they come to our attention, including pulling people out of bed and away from travel.”

Malware Bytes confirmed that they last noticed attacks on September 19, 2014, so the attacks are no longer occurring through either Doubleclick or Zedo.