does it work if you reset the browser?

Refresh Firefox - reset add-ons and settings

please note, that this might not be permanent solution if the malware is still active on your computer. also do a full system scan with the free version of malwarebytes or the other tools recommended at Troubleshoot Firefox issues caused by malware

OK, here is another crazy thing. Just went to "toubleshoot" and there is no "reset firefox" button on the top right like your link said there would be.

ah, sorry i didn't read your system information carefully enough. this feature was introduced with firefox 13, so you'll have to Update Firefox to the latest release first before you can proceed with that step...

Will get the update in a moment (checking email). Thank you. Didn't know an update was available...maybe I ignored the reminder!

In what way does that Trojan manifests itself?

You can also try:

• https://addons.mozilla.org/firefox/addon/searchreset/

Create a new profile as a test to check if your current profile is causing the problems.

See "Basic Troubleshooting: Make a new profile":

• https://support.mozilla.org/kb/Basic+Troubleshooting#w_8-make-a-new-profile

If the new profile works then you can transfer some files from the old profile to that new profile, but be careful not to copy corrupted files.

See:

• http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox

Do a malware check with some malware scanning programs on the Windows computer.
You need to scan with all programs because each program detects different malware.
Make sure that you update each program to get the latest version of their databases before doing a scan.

• http://www.malwarebytes.org/mbam.php - Malwarebytes' Anti-Malware
• http://www.superantispyware.com/ - SuperAntispyware
• http://www.microsoft.com/security/scanner/en-us/default.aspx - Microsoft Safety Scanner
• http://www.microsoft.com/windows/products/winfamily/defender/default.mspx - Windows Defender: Home Page
• http://www.safer-networking.org/en/index.html - Spybot Search & Destroy

You can also do a check for a rootkit infection with TDSSKiller.

• http://support.kaspersky.com/viruses/solutions?qid=208280684

See also:

• "Spyware on Windows": http://kb.mozillazine.org/Popups_not_blocked

Sorry for the delay in getting back, but the update to 13.0 and the reset worked...AdWare is gone! Thanks to all, and I will be keeping the suggestions for future pesky but harmless Trojans.