Malware researchers at Eset are warning about a fake Firefox download page that comes with nasty adware surprises. The malicious add-ons were Version 4.0 of Sothink Web Video Downloader and all versions of Master Filer. Uninstalling the extensions does not remove the trojan from a user s system, an anti-virus program should be used to scan and remove any infections. The fake Firefox page advertises version 3.5 the newest version is 3.6.
Source: https://threatpost.com/mozilla-admits-malware-sneaked-firefox-add-ons-020510/73495/