Nowadays when you install a security suite, no matter if it is free or paid, it is likely that at least one browser extension is added by it during installation to popular web browsers such as Firefox, Internet Explorer or Google Chrome.
When you install the most recent version of avast! Free Antivirus, the company's avast! Online Security extension will be added to the browser (it is also added if you install a paid version).
It has been designed to add protection to browsers specifically, and will warn you about phishing and malware sites while you are using the browser.
The extension has caused issues in the past for Firefox users, slow downs for instance or lag experienced while using the web browser.
While it is possible to disable the extension in Firefox's Add-ons Manager, there is no option to remove it completely from the browser.
The extension won't be loaded if you hit the disable button, and while you should see improvements right away, you may want to remove the extension completely from the Firefox web browser if you do not plan on using it ever again.
Tip: I have explained the method to delete Firefox add-ons without remove button here in detail.
The avast! Online Security extension for Firefox is not loaded into the profile directory of the browser. As you may know, there are other locations where extensions may be placed in to be loaded automatically by the browser.
It is also not located in the main Firefox installation folder on your drive. So where it is then?
You find the avast! Online Security add-on in the main Avast Software folder on your system under C:\Program Files\AVAST Software\Avast\WebRep\FF\
Note: before you go there, you need to disable the self-defense mechanism of the Avast application running on your system, or quit it, or remove the folders while booting into another operating system as they are protected otherwise and cannot be removed.
To disable the self-defense mechanism, do the following:
- Open the Avast software interface on your system.
- Click on the Settings link in the left sidebar.
- Click on Troubleshooting after the avast! Settings open up.
- Remove the check mark from "Enable avast! self-defense module".
- You will receive a warning message, continue here.
- Avast displays an on-screen prompt afterwards where it wants you to verify that this is intended.
The self-defense module is disabled then, and you can remove one or all of the extension folders under the WebRep structure afterwards.
When you have deleted the FF folder, or moved it to another location for safekeeping, you need to restart Firefox to complete the removal.
When you restart Firefox afterwards, the avast! Online Security entry is gone from the browser.
So how did the avast! Online Security add-on get installed in first place if it is not located in one of Firefox's traditional add-on locations?
The answer is by using the Windows Registry.
- Use Windows-R to bring up the run box, type regedit, and hit enter.
- Navigate to the key HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Mozilla\Firefox\Extensions using the folder structure on the left. This is the path for Windows 7, other versions of Windows may use HKEY_CURRENT_USER\Software\Mozilla\Firefox\Extensions instead.
- Here you find the avast! extension listed, and this is how it gets installed in the browser.
- The preference links to the folder where the extension is hosted in.
- You can remove that key to delete it from Firefox as well, but that requires a restart of the browser.
Note: Updates may introduce it again to the browser.