Troubleshoot Firefox issues caused by malware
Malware is short for "Malicious Software". It is a term generally used for software installed on your computer that is designed to infiltrate or damage a computer system without the owner's informed consent. Sometimes a problem with Firefox may be a result of malware installed on your computer, that you may not be aware of. This article describes what common symptoms are and how to prevent malware from being installed and get rid of them.
Table of Contents
How do I know that my Firefox problem is a result of malware?
Symptoms are various and depend on the malware but if you have one or several of these behaviors, you may have malware installed on your computer.
- Some ad popups display all the time, although you've blocked popups. For more information on blocking popups, see Pop-up blocker settings, exceptions and troubleshooting.
- Your searches are redirected to another site in order to feed you content from that website and you are being disallowed from blocking them. For more information, see What to do when searches take you to the wrong search website.
- Your home page has been hijacked. For more information on setting your home page, see How to set the home page.
- Firefox never finishes loading or can't load certain websites. For more information, see Websites show a spinning wheel and never finish loading and Firefox cannot load certain websites.
- Firefox crashes or hangs a lot. For more information, see Firefox crashes - Troubleshoot, prevent and get help fixing crashes and Firefox hangs or is not responding - How to fix.
- Firefox does not start. For more information, see Firefox won't start - find solutions.
- Problems with connecting to Facebook. For more information on problems with Facebook, see Fix problems with Facebook games, chat and more.
- Firefox keeps opening many tabs or windows. For more information, see Firefox repeatedly opens empty tabs or windows after you click on a link.
- Unwanted toolbars have been installed. For more information on customizing Firefox, see Remove a toolbar that has taken over your Firefox search or home page and How to remove the Babylon toolbar, home page and search engine.
How do I prevent malware from being installed?
There are simple rules to follow in order to prevent malware from being installed on your computer:
- Keep your operating system and other software updated: Installation of malicious software usually takes advantage of known security vulnerabilities in other programs, which may have been patched in later versions. Make sure you are using the latest version of each piece of software you use, including plugins using Mozilla's plugincheck website and Windows using the Windows Update feature.
- Don't install untrusted software: Some websites offer you software to accelerate your browser, to help you search the Web, to add toolbars that make things Firefox already does. Some unwanted programs also come bundled in software packages. Usually, these programs gather information on your browsing behavior that serve only people who designed them and interfere with Firefox. Make sure you install add-ons from Mozilla's add-on website and you uncheck unwanted programs in software wizards.
- Don't click inside misleading pop-up windows: Many malicious websites try to install malware on your system by making images look like pop-up windows, or displaying an animation of the website scanning your computer. For more information on detecting a misleading pop-up, see Pop-up blocker settings, exceptions and troubleshooting.
- Don't run a fake Firefox: Download Firefox from mozilla.org/firefox.
- Run anti-virus and anti-spyware real-time protection and scan your system periodically. Make sure your anti-virus and anti-spyware real-time protection is enabled. Scan your computer at least every month.
Mac security and malware protection
Mac systems tend to be regarded as more secure and, by default, more in control of available software, compared to Windows PCs. These Apple Support documents may be of help:
- OS X Mavericks: Protect your Mac from malware
- OS X Yosemite: Protect your Mac from malware
- OS X El Capitan: Protect your Mac from malware
- macOS Sierra: Protect your Mac from malware
- About the "Are you sure you want to open it?" alert (File Quarantine / Known Malware Detection) in OS X
For information of a more technical nature, this Apple Support article discussion has a comprehensive summary of advice, recommendations and linked articles for Mac users:
How do I get rid of malware?
The Wikipedia article Linux malware has information and recommendations for Linux users.
How do I get rid of malware?
Recent Microsoft supported Windows is likely to have basic free anti-virus software built in or available free from Microsoft. If your anti-virus and anti-spyware software hasn't detected malware, scan your system with the free malware scanning programs listed below. You should scan with all programs because each program detects different malware and make sure that you update each program to get the latest version of their databases before doing a scan.
Need more help?
You can ask for help in a forum specializing in malware removal, such as those listed below: