Twofer Malware: Rogue Internet Explorer Plugin Infects Firefox

Malware is downloaded and installed by users who believe they are upgrading Flash Player for Internet Explorer. Fake Firefox add-on (identified as Trojan.JS.Redirector.KY) screens any new web pages loaded into the browser and what kind of information (images, videos, maps, advanced searches) is fetched for the user. At this point, switching browsers wont help. If you want to extend or upgrade your browser of choice, use the official distribution channels.”]

Source: https://www.bitdefender.com/blog/hotforsecurity/twofer-malware-rogue-internet-explorer-plugin-infects-firefox/