You may be experiencing the "hang at exit" problem when it restarted after the update. I did, and that is a problem that I had never experienced before. Follow the instructions below for "Stop the Firefox process" ONLY. Try exiting (using Firefox button > Exit OR File > Exit (if using the Menu Bar) and re-starting several times after that. If the problem persists, follow the remainder of the instructions. My problem was solved by performing "Stop the Firefox process" only one time.

1. Stop the Firefox process:
   • Mozillazine - Kill application
   • Windows 7 users click here
2. Why Firefox may hang:
   • Firefox hangs (see Hang at exit)
   • Firefox hangs (Mozillazine) (see Hang at exit and Closing Firefox properly)
   • Firefox is already running but is not responding
3. Use Firefox Safe Mode to find a problem with an Extension or Plugin:
   • Don't check anything when entering Safe Mode, just continue
   • If the problem does not occur in Safe Mode it is probably and Extension or Plugin causing the problem
   • See:
     • Diagnose Firefox issues using Troubleshoot Mode and Safe Mode (Mozillazine)
     • Troubleshooting extensions and themes
     • Troubleshooting plugins
     • Basic Troubleshooting

If this reply solves your problem, please click "Solved It" next to this reply when signed-in to the forum.

There is a known problem with Firefox 6 crashing due to particular malware. A problem Safebrowser will now be aware of. The Trojan concerned is able to affect Firefox and IE Windows browsers.

The cure is to do a full system scan with up-to-date security software. See also the article firefox crashes, noting that the article itself is in the process of being improved.

We do not know this is causing your specific problem but it is a possibility. If the Trojan is involved, it may apparently causes actual crashes with Firefox in some instances, and it should be possible to obtain Crash IDs from those crashes. Note also

• the malware is likely to affect search results if it does not crash the browser.
• the malware currently does not seem to crash the latest Firefox 7 which will be on the Aurora or Beta channel, but that will still not yet be immune to the Trojan, merely less likely to crash

John99 said: There is a known problem with Firefox 6 crashing due to particular malware. A problem Safebrowser will now be aware of.

I was aware of that trojan and was also aware that:

• the trojan has been around for over a year
• generally anyone infected by that trojan would most likely have experienced search problems preceding the update to Firefox 6
• a change was made in Firefox 6 that fixes a function that the trojan was using; I believe the change was made in Firefox 6beta5
• I keep myself aware of such threats, without assistance

As for my system, I regularly scan with multiple on-demand scanners and have not had reported infections and have experienced no search problems on any of my systems during the past year. I also have a very good full-time, on-access scanner running at all times. I also run my systems behind multiple layers of routers. And, as my moniker implies, I am a safe browser. I therefore, do not believe that the "hang at exit" on my system when updating from Firefox 5.0.1 to Firefox 6.0 was caused by that trojan.

There can be several other causes for "hang at exit" and I am aware of those causes.

Had you displayed the courtesy of sending a PM rather than making your pointed remark/implication, I would have posted the above in a PM to you, However, since you chose to make your implication publicly, I have replied publicly!

I was merley pointing out you had already posted in the other thread and that you are aware of the trojan problem.

a change was made in Firefox 6 that fixes a function that the trojan was using; I believe the change was made in Firefox 6beta5
from a cursory look at the information I am under the impression changes made resulted in the trojan now causing Crashes in Firefox 6, whereas previously the problem was with the searches.

I considered it appropriate to mention this Trojan in this thread as possibly it will be looked at by users of Firefox 6 who are experiencing crashes due to the Trojan. You may not find my comments useful, but anyone with the Trojan may.

The fix to Firefox 6,

• which previously allowed the trojan to interact with Firefox in a way to cause search problems in version of Firefox prior to version 6,
• now causes Firefox 6 to crash, if the user is infected with the trojan.

Apparently the hold up was a small window that popedup behing all the other stuff on the screen. It dealt with incompatible firefox plugins. I responsed to it, it closed and then firefox came up. That plugin window (widget?) should have been set to be on top of all other screens. I am probably not using the correct terminology, but hopefully you get the idea.

So, is everything working now?

See Re-enable add-ons that were disabled when updating Firefox for steps you can take to deal with incompatible Firefox add-ons.

All seems to working OK, but it has been only a short while since I found what appeared to be the problem. I'll know more tomorrow. Also, I'll check Alice's suggestion about add-ons when I have more time.

I appreciate everyone suggestions as they add to my knowledge of Firefox.

My problem (windows 7) is NOT a 'hang at exit' nor one where firefox processes need to be killed. I did find and quarantined two trojan programs.. finalvbto.exe and finalvcto.exe. After I removed them, I uninstalled V6, reinstalled it, but the symptoms are the same - a window very briefly pops up, then goes away followed by the standard crash window asking if I wish to report and restart Firefox. Working with IE 9 was a bad scene also trying to download anything - Full of bugs. Had to download Google Chrome so I could download Firefox V5 and fall back to what works.

Hi rftabal, ( & anyone with crashes or search problems)

It may help if you start a new thread, as you are specifically mentioning Trojans are detected, and that Firefox 6 Crashes but Firefox 5 does not. To me at least your symptoms do sound rather like what may be expected if you do still have the Trojan malware problem.

If you do post back

• could you mention whether you tried to obtain crash IDs ?
• are you noticing any problems with searches ?
• what did you use to find and kill the two trojans - name and version of security software
• I am guessing the Microsoft security software for dealing with the threat is effectively free to registered users of a free MS OS, have you considered trying that ?

You may note the Trojan that is causing problems with Firefox 6 does create files with pseudo random names, and IIRC may create multiple instances of itself, and so may be difficult to fully remove.

• I also recall mention of this trojan affecting IE & Firefox, I am not sure if it affects Google Chrome.
• the Trojan involved is per the link I mentioned is known at MicroSoft as "Trojan:Win32/Sefnit.A"
• I did not find info in a web search relating to malware with names finalvbto but that may not be surprising if random names are being used.

Sorry to have strayed off topic from the thread title,
but this does seem a potentially important topic for those having problems on upgrading, as I said starting a new thread would be a good idea rather than posting answers in this thread,

• if it is thought malware could be the problem,
• or if crashes are involved.