Ubuntu – Suspicious connections coming from Firefox (possible malware)

I don't think there's much value in tracking down exactly what the problem is. Of course there is always some value but I can't guarantee you'll ever find out what the problem is.

In Etcher-Sketch terms, it's easier to just shake it until you have a blank canvas and then, if you want, you can pull back some of the less-likely-to-be-infected things (general settings, bookmarks, etc).

But the easiest install vector for malware in Firefox is through its extensions manager. You can check the extensions.ini file in the active profile for anything suspicious, but as I say, it may bear no fruit.

To get things back to normal, let's shake Firefox:

Nuke the old profile.

Here's a little script that moves the old profile to another location. I'm making this up as I go, so there might be a bug or two in it. You should be able to copy and paste this into a terminal.

cd ~/.mozilla/firefox/
export FFPROFILE=`cat profiles.ini | grep "Path=" | sed 's/^Path=//'`
mv $FFPROFILE $FFPROFILE.BAK
rm profiles.ini

When Firefox next launches, it will create a new profile.

Save bookmarks, saved passwords, etc

After firefox has created the new profile, you can go to ~/.mozilla/firefox/ in nautilus and copy back some of the files into the new profile and then deletes the profile configuration file so that Firefox has to create a new profile. Start by closing Firefox and then punch these lines into a terminal:

cd ~/.mozilla/firefox/
export FFPROFILE=`cat profiles.ini | grep "Path=" | sed 's/^Path=//'`
export OLDFFPROFILE=`ls -1 | grep .BAK`
cp $OLDFFPROFILE/*.sqlite $FFPROFILE/

You can of course do both these parts manually. It's actually easier to do it manually, you just need to know your way around the filesystem a little better. I was just thinking of you needing to do push this off to somebody else... it might just be easier if they copy and paste it into a terminal... Or you do it via SSH.

What is slow? Switching between tabs, opening a site, scrolling the window...? It might be your graphic drivers. If you have an nVidia card try installing the non-free nVidia drivers rather than the stock ones that come with Ubuntu.

UPDATE:
Okay, if it's the network access that is slow my guess would be that you have IPv6 enabled. Try running sudo apt-get update from a terminal window, and if you get the same 5-10 second pause then try disabling IPv6. The "quick" way to do that (just for testing) would be to edit /etc/gai.conf and add the following line to it:

precedence ::ffff:0:0/96  100

Restart firefox and see if that speeds things up. If it does, a better way to disable IPv6 is described in this answer to the question How to disable IPv6 in Ubuntu 14.04?