In the last two weeks, Mozilla has reviewed and banned 197 Firefox add-ons because they were executing malicious code. Mozilla also disabled the malicious apps in the browsers of the users who have already installed them. Most of the banned apps have been developed by 2Ring, a provider of B2B software. The apps were using obfuscation to hide their source code and were downloading and executing code from a remote server, a behavior that violates the policy of the portal. The organization also banned for malicious behavior other 30 add-on apps.”]
Source: https://securityaffairs.co/wordpress/96860/hacking/mozilla-banned-firefox-add-ons.html