Hidden addons/plugins? Removal?

My friend’s PC is infected with maleware. Firefox takes forever to load (if ever) normally but if I launch FF in its “safe mode”, opens immediately (a sure sign of a bad addon/plugin.)

But when I check, it shows no unusual addons installed.

Is there a utility that can identify & remove hidden addons/plugins? TIA

There is no such thing as a hidden add-on (apart from system add-ons which need to be signed with a special mozilla key that malware never ever should get its hands on).

If you do not trust the list in about:addons, you can cross-check about:support.

In general, malware extensions when discovered and reported to mozilla can be blocklisted, so they’re removed automatically. However, malware may try to break this mechanism, which has to be fixed outside of Firefox.

The classic advice of figuring out a bad extension is to use the “half-split” troubleshooting method, where you disable half of all extensions, and if that solves the issue the extension is in the other half, else it’s in the current half. Then you half that half and do the same etc.

Thanks for the reply.

I’ve had situations in the distant past where a malicious plug-in did not appear in the list of installed plugins and therefore was incredibly difficult to remove. I wasn’t sure whether or not that was still the case.

He has/had one “infected” Addon that disabling resolved. The addon itself was legit [“Tweepsmap”] and he got it off their official website, yet somehow down the line, it clearly became “infected” because disabling it made his problems go away. But the infection goes much deeper and the infected plugin keeps reappearing.

So I need a utility to detect & fully remove the infection and all its parts.

Then you should probably follow https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-caused-malware

As I said, this means there’s outside influence.

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There are TONS of hidden plugins/addons in all versions of FF.

I’ve deleted them all now, but they’re in C:\Program Files\Mozilla Firefox\browser\features

From memory there is a screenshots app, pocket and at least 3 more. Delete all the .xpi files in there - they are totally unnecessary and are of major privacy concern!!

If that wasnt enough, there are tons more, from amazon, bing, google and others to be found.

To find them all - install ccleaner and in it, theres a tool for finding all of your hidden browser pugins… in cccleaner go to ‘tools’ then ‘browser plugins’ and then ‘firefox’ - it has options for FF, IE and Opera.

Open that up then you will see TONS of stuff inclucing in FF that you had NO IDEA was there!!

Delete or disable EVERYTHING - NONE of it is necessary for any form of browsing - I’ve deleted it all and had zero negative effects.

Also type in about:config type safebrowsing and disable ALL hits - safebrowsing is google safe search built in to FF - it constantly sends data to GOOGLE from your FIREFOX

Also type ‘google’ into about:config and delete everything, all references and all links.

Congratulations - you finally got rid of 1% of the TRACKING and PRIVACY INVADING stuff HIDDEN in FIREFOX


which is the part you omitted:

Why does one have add-ons of Amazon, Wikipedia, Twitter, “Screenshots”, DuckDuckGo, in Firefox that are not visible (except, indeed, in CCleaner)?

System add-ons are similar to add-ons that you install. The main difference is that they are not installed by the user but ship with Firefox or are pushed to Firefox when the need arises.

Since when do the Mozilla developers think that I need Amazon, Twitter, Wikipedia, et al, in ‘my’ Firefox install?

If these are not att-ons, then why does CCleaner show them?

@ohyes, thank you for showing where those “add-ons” are to be found.

–EDIT: Ah, those seem to be the “alternative” search engines…

Dear Sir,

What do you call this. I am unable to remove it. It stops my browsing . So what is it how can i remove it

“Add-ons Search Detection” stops your browsing? I believe it is meant to keep an eye on your search engines and doesn’t do anything related to browsing. If you have a problem with Firefox not browsing, I suggest posting on Mozilla support:



Could you please share some more information about this problem?

For instance, could you please share the troubleshooting information that you can find by visiting about:support? There are two buttons to copy the data to your clipboard, and you can then send the information to me by private message OR email (wdurand[AT]mozilla.com).

In addition, and given this problem is related to an add-on, it would be very valuable to us to have two other files from your profile: the extensions.json and the addonStartup.json.lz4 files.

Those two files can be found by first opening your profile folder with a file manager, which you can do from about:support, see “Profile Folder” in the first section (“Application Basics”). Please also send me the information privately.