Ads on Yahoo home page in several European countries, were delivering a malware that mined bitcoins on 2 million infected PC.
The malware used flaws in Java modules on the infected computers. Only European users were infected, visitors from in North America, Asia Pacific and Latin America weren’t. The malware only targeted PCs (running windows), thus users of Apple Macs or mobile devices were not affected.
Yahoo released a statement saying: “From December 31 to January 3 on our European sites, we served some advertisements that did not meet our editorial guidelines – specifically, they spread malware.”
"We will continue to monitor and block any advertisements being used for this activity," the company added. "We will post more information for our users shortly."