This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Buscar en Ayuda

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

prefs.js -- malware inserted

  • 1 respuesta
  • 1 tiene este problema
  • 1 visita
  • Última respuesta de James

more options

The Firefox prefs.js file was quarantined by avast yesterday. Message indicated malware had infected the file. Now when I click on the Firefox icon the MSN browser comes up. How can I get back to using Firefox safely? Can I uninstall Firefox, then re-install it to make the problem go away?

The Firefox prefs.js file was quarantined by avast yesterday. Message indicated malware had infected the file. Now when I click on the Firefox icon the MSN browser comes up. How can I get back to using Firefox safely? Can I uninstall Firefox, then re-install it to make the problem go away?

Todas las respuestas (1)

more options

^Ignore the above reply by donthavecow

https://support.mozilla.org/en-US/questions/1371864

For some Firefox (and Thunderbird) users who use Avast or AVG briefly had these scanners quarantine the prefs.js file even though Avast/AVG said they fixed the False Positive issue the day before.

If you still have the prefs.js file you can out it back in your Profile.