Mozilla has issued a warning that two add-ons available from AMO (addons.mozilla.org, the Mozilla Add-ons website) were infected by malicious code capable of infecting Windows computers.
According to a security notice on AMO’s blog, the Master Filer add-on was infected by the LdPinch password-stealing Trojan, and Sothink Web Video Downloader version 4.0 was infected by a version of the Bifrose backdoor Trojan horse. (Update: Mozilla reports that Sothink Web Video Downloader is not infected after all).
Judging by the statement on the Mozilla Add-ons blog, a fair few people could have found that their Windows computers were infected:
Master Filer was downloaded approximately 600 times between…
Read more in my article on the Naked Security website.