The ransomware page is being pushed onto unsuspecting users browsing regular sites but in particular when searching for popular keywords.
Warnings appearing to be from the FBI tell the victim: “you have been viewing or distributing prohibited Pornographic content.. To unlock your computer and to avoid other legal consequences, you are obligated to pay a release fee of $ 300.”
The report details one method to escape the ransomware involving resetting Safari, but misses a far simpler tactic: Simply holding down the Shift key while relaunching Safari will prevent it from reopening windows and tabs from the previous session. Users can also completely disable the reopening feature across OS X from the General pane of System Preferences. Many OS X users may, however, be unfamiliar with such options and find themselves trapped by the ransomware webpage.
The report notes that the ransomware authors are targeting users based on popular search terms, with one example stumbled upon through an image search result for Taylor Swift on Bing.