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 malwares from being installed and get rid of them.

How do I know that malwares are installed on my computer?

Symptoms are various and depend on the malware but if you have one or several of these behaviors, you may have malwares installed on your computer.

• Some ad popups display all the time, although you've blocked popups. For more info on blocking popups, see Pop-up blocker settings, exceptions and troubleshooting.
• You are unintentionally redirect to some websites in order to feed you content from that website and you are being disallowed from blocking them.
• Your home page has been hijacked. For more info on setting your home page, see How to set the home page.
• Firefox crashes a lot. For more info on troubleshooting crashes, see Troubleshoot Firefox crashes (closing or quitting unexpectedly).
• Firefox does not start. For more info, see Firefox won't start - find solutions.
• Unwanted toolbars have been installed. For more info on customizing Firefox, see Customize Firefox controls, buttons and toolbars and Find and install add-ons to add features to Firefox.

How do I prevent malwares from being installed?

There are simple rules to follow in order to prevent malwares from being installed on your computer:

• Use the latest version of each piece of software: Installation of malicious software usually takes advantage of known security vulnerabilities in other softwares, which may have been patched in later versions. Make sure you are using the latest version of each piece of software you use, including Windows updates.
• Don't install untrusted softwares: Some websites offer you softwares to accelerate your browser, to help you search the Web, to add toolbars that make things Firefox already does. Usually, these softwares gather information on your browsing behavior that serve only people that designed them and interfere with Firefox. If you want to install a safe add-on, privilege the Mozilla add-on website.
• 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 info on detecting misleading pop-up, see Pop-up blocker settings, exceptions and troubleshooting.
• Run anti-virus and anti-spyware real-time protections and scan your system periodically. Make sure your anti-virus and anti-spyware real-time protections are enabled. Scan your computer every two weeks or every month.
• Don't run a fake Firefox: Download Firefox from mozilla.com.
  Note: Please report misuse of the Firefox trademark using the Mozilla Violating Website Report page

How do I get rid of malwares?

If your anti-virus and anti-spyware softwares haven't detected malwares, scan your system with other free malware scanning programs. You need to scan with all programs because each program detects different malwares and make sure that you update each program to get the latest version of their databases before doing a scan.

There are also specialized forums for malware removal such as those listed below, where you might be able to get more help:

• Bleeping Computer Forums
• Spyware Warrior Forums
• SWI Forums