Avast suddenly doesn't like several Firefox add ons

Avast Free Antivirus / Premium Security
1

Today I started up my browser Firefox 33.1 only to find many, but not all, of my add ons have disappeared and are not listed in the Add-ons Manager anymore. Is there some reason Avast would suddenly dislike most of my Firefox add ons and delete them? Is there a way to tell if Avast was the program to delete them? I have a similar question posted in the Firefox forum at Mozillazine and the common thread was they all were using Avast.

Quote from: lukor on Yesterday at 05:38:08 PM

Hi guys, thanks to all for the information posted. We have been able to identify the problem now. Browser Cleanup is responsible for this issue. A bug in the component calculating hashes of the extension packages cause (only in some rare cases) deletion of the wrong file - the original instead the packed one. 
Sorry for that and thanks again for your help obtaining the repro steps for us.

The Browser Cleanup team is now working on a fix, which will be delivered via a VPS update shortly (tomorrow).

Lukas</blockquote>

So how will I know when is safe to reinstall my add-ons? People, inducing me, seem to be fuzzy about what a “VPS” is exactly. I think it is some sort of virus signature, but since Avast gets several of these a day, I want to know how I’ll know which one was the right one.

By way, when I first had this problem, my first thought was I had a virus and I ran a couple scans looking for it. Having an antivirus program make me think I have a virus seems to me to be a very bad thing. It would have been really nice if there were some sort of log that told me what Avast had done so I could know for sure it was overreacting. I looked in the vault and scan history and there was nothing.

UPDATE: November 21, 2014

Now that the crisis seems over, I have a few words for Avast.
Putting aside the last few days and the trouble I have been through trying to remember what Firefox add-ons were missing and reinstalling them, the thing that stands out the most about this episode to me is I had no idea how to tell if Avast was deleting my files. I checked Virus Chest and Scan History and they both said nothing. This lead to a panic and scramble to find what malware or virus was capable of attacking Firefox and was strong enough to get past Avast.

The other thing that comes to mind is since Avast could delete things without keeping a record, what other files on my computer might it be deleting? One of the Avast techs said it was caused by Firefox XPI format, but how would I know if Avast didn’t like something else? A few weeks ago Avast took a disliking to a program that has been on my computer for years. At least then I found it in the Virus Chest and could create an exception for it. Now I’m constantly nervous and thinking of switching to another program.

BTW: I know what CAPTCHAS are for, but yours are a lot harder than most I have come across. I’m human and it sometimes still takes me a couple tries.

2

avast deletes them if you run the browser cleanup tool and let avast to delete them.
Only other time that avast deletes them if they are detected as malware.

3

I have the same problem and judging from Mozilla forums, so do others:

http://forums.mozillazine.org/viewtopic.php?f=38&t=2888363&p=13876775#

The add-ons are deleted automatically, not via browser cleanup tool and there are no reports of malware being detected. I witnessed it happen “live” as I was in my add-ons manger list, add-ons being removed automatically.

Something very fishy is going on. I’ve turned off HTTPS scanning, because that has caused many issues and so far I haven’t had the issue since HTTPS scanning went off again.

4

Also experienced twice in two days. Did not link to Avast unstil now. Add-ons in question:
Open With
Classic Theme Restorer

Could be linked:
https://forum.avast.com/index.php?topic=160114.0

5

It removed pretty much every of my add-ons, every one of them very popular add-ons.

6

I guess I’m just lucky again and none of my 33 add-ons on both XP and win7 systems (running firefox 33.1.0) are effected.

7

I have those 2 extensions (among many others) in several profiles across 3 laptops and have had no issues. I have HTTPS web scanning enabled. I’m currently running Firefox 33.1.1, updated yesterday after it was released. I’m not using Firefox Sync.

8

I am using the Firefox Sync (including sync add-ons) on both systems so if it happened on one it would migrate/sync to the other.

I don’t have the Avast Browser Cleanup installed, nor do I use the firefox Avast On-line Security add-on. HTTPS scanning is enabled on the win7 system, but not compatible in the XP OS.

9

Same here, except all my machines are now Win 7. My desktop WinXP Pro SP3’s power supply fried taking the motherboard with it. I was able to use a SATA/USB adapter to retrieve the data and then image backup the 2 160GB hard drives. The machine was then taken to my grandson who is salvaging the drives and various other parts that are still usable.

10

I can confirm this bug too :frowning:

Greetz, Red.

11

I can confirm this too. Since the last program update Avast removes half of my firefox addons automatically on every system startup. This is very annoying. Would be nice if some avast official can provide us with a statement about the problem.

12

Huh. That happened to me earlier today too. The catalyst was updating FF from 33.1 to 33.1.1. When FF restarted itself after updating many of my addons were missing. Only my British English Dictionary and WOT were still there. I’ve had to reinstall them one by one.

13

Latest Avast reportedly deleting Firefox add-ons

http://www.ghacks.net/2014/11/16/latest-avast-reportedly-deleting-firefox-add-ons/

14
The catalyst was updating FF from 33.1 to 33.1.1. When FF restarted itself after updating many of my addons were missing.
Could it be related to a firefox update then ?
15

I don’t have this problem,but I am updating almost everything manually.

16

No problems here with FF ESR.

17

Having just just read the new posts on this topic, I did a manual update from the 33.1.0 UI (XP) and firefox has rebooted and I still have all of my add-ons that I started with. Just about to do the same on my win7 netbook - update has completed and restarted - all add-ons are still in place.

18

If this was an issue with the latest Firefox 33.1, this would be more widespread. But every single person, who has this problem, is using Avast.

This can be related to Avast messing up Firefox, when updating to 33.1. This did happen to me after I’ve updated my work PC to 33.1 and then the firefox sync feature migrated the settings to my other PC.

19

+1

20

I’m having no problems with losing Firefox extensions with Firefox 33.1.1 and Win 7 SP1. I don’t have AOS, GrimeFighter, nor Browser Cleanup installed, though.

There is the assumption that Browser Cleanup must be given permission to remove what it finds, but the assertion by a user on Mozilla Bugzilla https://bugzilla.mozilla.org/show_bug.cgi?id=1099973#c5 has this to say.

 Martin Pecka 2014-11-16 05:48:42 PST

And one last thing today - I've checked Avast GUI and there was really an option in the Browser Cleanup tool to clean browsers automatically. I'm sure I haven't turned this option on!

Since I don’t have Browser Cleanup installed (and no desire to do so), I can’t check this.