Yahoo ad network used to deliver malware - comments from Webroot
August 2015 by Webroot
It has emerged that cybercriminals are utilising Yahoo’s own ad network to deliver malware and ransomware to unsuspecting users. Research by Malwarebytes found that the campaign has the potential to be one of the largest malvertising attacks seen in recent years, with Yahoo recording an estimated 6.9bn visits per month.
“With the pure scale and size of Yahoo – many people may have fallen victim to this attack. Monetary gain is the primary motivation for attacks of this nature and in many cases, ads are just traps for additional attacks. This exploit is an indication that potential breaches are heading in the direction of becoming more complex in nature, and with further reaching effects on a larger number of end-users. With an estimated 6.9 million users per month, this exploit raises serious questions about the size of this attack and Yahoo’s security processes.
“Exercising prudence when obtaining and installing software is crucial to staying protected from these types of attacks. End-users should keep in mind that often a quick search can give useful information on the general level of public trust. To stay protected, I encourage users to use the Chrome browser along with an ad-removal extension. There are number to pick from, and using this combination offers the best chance of preventing an ad network redirect to an exploit kit.”