It is worse for the updated Firefox 66.0.3
Now only did we have the certificate snafum but the update auto installs the Baidu Search plugin as well.
https://www.ghacks.net/2019/04/10/mozilla-releases-firefox-66-0-3/
I do not want any Chinese spyware installed thank you.
I am glad I use Ccleaner as it shows what plugins and extensions are installed for every browser - and allows easy disabling of them and the location to permanently delete them.
What anoys me is these are hidden plugins - and that aint cool.