Every month, several new extensions are sent to the addons.mozilla.org page. Some creative, some other useful and sometimes malicious. The problem is that all are available once they are sent, under the category “experimental”, then only then be considered “normal” when they pass by an analysis of its code by the staff of Mozilla.

An add-on called Mozilla Sniffer, sent on June 9, had reviewed its code (and added to the blocked list) only on July 12. The extension, which was presented as a modified version of another extension (TamperData) panned any login transmitted via Firefox and sent to a remote address unrelated to the site that was accessed. It has, meanwhile, about 1,800 downloads and about 300 daily users. Mozilla has recommended that these users to uninstall immediately and to change their passwords as soon as possible.

Another extension was not exactly maliciously call CoolPreviews, but its code leaving the system vulnerable to any site that would create a malicious link specially programmed to exploit the flaw of the add-on.

Mozilla, with these two cases, realized that the system’s current site allows many downloadable extensions become dangerous, even just showing up when the visitor chooses to view them and install them. So the idea now is to only allow viewing of these extensions.

Therefore, be careful when you choose an add-on to install in your PC!

Via: ZDNet.