Please have a look here. The trojan should not affect Firefox, but you would do good by scanning your computer for malware afterwards.

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 if you don't already have one. Windows 8/10 have antivirus protection built-in.

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

If you closed Firefox using the task manager, it may just restore the last session at the next launch despite the startup settings, so that’s the good news - it does not mean your start page settings are not retained.

Please report back how things go.

You can set browser.sessionstore.max_resumed_crashes to 0 on the about:config page to get the about:sessionrestore page immediately with the first start after a crash has occurred or the Task Manager was used to close Firefox. That will allow to select what tabs/windows to restore.

You can open the about:config page via the location/address bar. You can accept the warning and click "I'll be careful" to continue.

• http://kb.mozillazine.org/about:config

I don't think this is malware. My system is protected. It's the script on that web page. Trying to close the browser window causes a freeze. I force crashed the browser to free it.

bp-8f4642b4-67ca-4041-9f5b-fc3511170910 Signature: @0x0 | __RtlUserThreadStart | _RtlUserThreadStart

Nice song. Cute dog.

Note: If I use disallow Script Button first there is no problem. https://addons.mozilla.org/en-US/firefox/addon/disallow-script-button/

I can easily close the tab with a middle-click on the tab bar. I go a script error and stopped the script and the tab closed.