Adware attacks against OS X are on the rise this year, says a report by anti-virus company Doctor Web. The Russian firm recently discovered another threat, Trojan.Yontoo.1, which has quickly become the most prominent adware trojan attacking Apple desktops and laptops.
The trojan worms its way onto your computer through websites that require you to install a plugin to view the content of the site. The most common vector are movie trailer websites that prompt you to install an HD Video player or similar plugin. Instead of a media plugin, unsuspecting users will download the trojan.