Have some kind of virus or trojan horse -- dozens of spam messages are being sent out from my PC. Is there anything I can do?

Question

The messages do not show up in my Sent folder. Many of them are sent to dead email addresses and the only way I know that this is happening is from the "failure to deliver" messages from the Mail Administrator.

Answer 1

General Malware SCAN for your System
* [http://www.microsoft.com/security/scanner/default.aspx Microsoft Safety Scanner]
* [http://www.malwarebytes.org/products/malwarebytes_free/ MalwareBytes' Anti-Malware]
* [http://support.kaspersky.com/faq/?qid=208283363 TDSSKiller - AntiRootkit Utility]
* [http://www.surfright.nl/en/hitmanpro/ Hitman Pro]
* [http://www.eset.com/us/online-scanner/ ESET Online Scanner]
[http://windows.microsoft.com/MSE Microsoft Security Essentials] is a good permanent antivirus for Windows 7/Vista/XP if you don't already have one.
Further information can be found in the [[Troubleshoot Firefox issues caused by malware]] article.
Create a new profile as a test to check if your current profile is causing the problems.
*https://support.mozilla.org/en-US/kb/profiles-tb
If the new profile works then you can transfer files from a previously used profile to the new profile, but be cautious not to copy corrupted files to avoid carrying over the problem
*http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Thunderbird
*http://kb.mozillazine.org/Profile_Manager