What I so love about Mozilla Firefox is the collection of add-ons to expand functionality in virtually any sense. However, this can also expose users of the add-ons to a risk. Earlier this week Mozilla disclosed that a pair of add-ons found at http://addons.mozilla.org site included Trojans.
The two add-ons involved are Master Filer, a download manager and Version 4.0 of Sothink Web Video Downloader. Windows users that have downloaded and installed these add-ons would be affected by Malware that could potentially get a hold of their information. It is recommended by Mozilla that potentially impacted Windows users run an antivirus program. Just uninstalling the affected add-ons does not remove the Trojans.
In an article at E-security Planet we read
As to how a pair of infected add-ons ended up on Mozilla’s site, Mozilla faults its scanning tool.
“AMO performs a malware check on all add-ons uploaded to the site, and blocks add-ons that are detected as such,” Mozilla wrote in its advisory. “This scanning tool failed to detect the Trojan in Master Filer. Two additional malware detection tools have been added to the validation chain and all add-ons were rescanned, which revealed the additional Trojan in Version 4.0 of Sothink Web Video Downloader. No other instances of malware have been discovered.”
I guess this is all the more reason again to keep your security software updated.