Malwarebytes is just one tool to locate and remove Malware. General consensus around here is to follow this.

Sometimes a problem with Firefox may be a result of malware installed on your computer, that you may not be aware of.

You can try these free programs to scan for malware, which work with your existing antivirus software:

• Microsoft Safety Scanner
• MalwareBytes' Anti-Malware
• Anti-Rootkit Utility - TDSSKiller
• AdwCleaner (for more info, see this alternate AdwCleaner download page)
• Hitman Pro
• ESET Online Scanner

Microsoft Security Essentials is a good permanent antivirus for Windows 7/Vista/XP if you don't already have one. Windows 8 has antivirus built-in already.

Further information can be found in the Troubleshoot Firefox issues caused by malware article.

Did this fix your problems? Please report back to us!

Dear Mozilla: I am aware that I have malware installed on my computer -- and that Chrome and Firefox were affected (IE Explorer v11 was not affected). I was able to get Chrome "fixed" by a reset in Chrome, whereas all actions tried to date on Firefox have failed (including a "refresh") . FYI, I was using the solution you recommended in your most recent reply and downloaded, installed and ran (twice) the Malwarebytes application. Are you suggesting that I download, install and run all the other free programs in the hopes that one of them uncovers the issue?

What I had hoped for: i) your team would look at the diagnostics I attached with my question and come up with a general consensus for the cause/solution of the issue; ii) your team would provide a general consensus as to whether this Firefox malware constitutes a threat to my PC, and what those threats might be.

I do like like Firefox and it has been my default browser. However, with the malware issue, it is effectively unusable. While I hope to continue to use Firefox, I have invested 5 hours so far to repair the issue with no luck. I do not wish to continue to spend additional hours troubleshooting with no prospect of a resolution in sight. I am also concerned that this malware, active when Firefox is running, could affect other aspects of the operation of my PC, a risk I wish to avoid.

Therefore, I will temporarily switch my default browser from Firefox and will await an analysis/solution to this issue. If you need additional diagnostic reports other than the one I attached in my original question, please let me know.

Yes, run all those other anti-malware programs. The others may catch stuff that Malwarebtyes missed.

This forum is "staffed" mostly by other Firefox users who volunteer their time here, especially on weekends, so please watch that "holier than thou" attitude.

Dear Edmeister: Understood. I went to respond to your e-mail to me, but I note that the message content in this thread is different from the message you sent to me with its more personalized content. So, to respond to your other e-mail, as you and your colleagues are out of the tread then consider this question closed. I did not realize that you were unpaid volunteers and can emphasize with your frustration. I also would be frustrated to volunteer to identify solutions for users that have posts with which I take issue. Consider the matter closed.