Firefox crashes

This crash signature is possibly related to malware: *[https://bugzilla.mozilla.org/show_bug.cgi?id=434403 bug 434403] - Startup crash [@ nsDocShell::SetupNewViewer(nsIContentViewer*)] [@ nsCOMPtr_base::assign_with_AddRef(nsISupports*) | DocumentViewerImpl::Close(nsISHEntry*) ] (causes: Backdoor.Ulrbot.C Trojan, Spector Pro) ---- Do a malware check with some malware scanning programs on the Windows computer.<br /> You need to scan with all programs because each program detects different malware.<br /> Make sure that you update each program to get the latest version of their databases before doing a scan.<br /><br /> *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