Hi, Firefox downloaded from mozilla.org doesn't contain malware, although downloads from other sites may come bundled with junk.

Open the Add-ons Manager (Ctrl+Shift+A) > Extensions/Plugins and disable/remove anything suspicious.

You can also check your Firefox Desktop shortcut for corruption: Right click on it > Properties, and in Target, make sure there is no sign of the malware. If there is, delete that part of it. Or if it's easier, you can just delete it and recreate a new shortcut. More: Wrong home page opens when I start Firefox - How to fix.

Another thing you can do, is to search for the malware in your PC's search box; also look in Control Panel > Programs for anything installed on the date this started that you don't recognize.

You can also try these free programs to scan for malware, which work with your existing antivirus software:

• Microsoft Safety Scanner
• MalwareBytes' Anti-Malware
• Anti-Rootkit Utility - TDSSKiller
• AdwCleaner (for more info, see this alternate AdwCleaner download page)
• Hitman Pro
• ESET Online Scanner

Note that not all removal programs will detect all malware, so you may need to run several or all of them.

Further information can be found in the Troubleshoot Firefox issues caused by malware article.

Did this fix your problems? Please report back to us. Thank you!

It’s very sad, but many software downloaders/ installers will trick you into installing not only their program, but other programs as well.

You have heard of the fine print in shady contracts, right? Well, some installers you need to look at the itsy bitsy teeny weeny fine print.

You are thinking you are giving the installer permission to install the program you want by using the recommended option. But if you use the Manual Option Instead, you discover all kinds of stuff that you do not even know what it is or what it does.

From now on, everyone needs to Use The Manual Option to put a stop to this.

Note that these programs can also change browser/computer settings.

As from your reply, i check my BigFarm and BigBang Desktop shortcut for corruption: Right click on it > Properties, and in Target. but the target file is exactly the firefox.exe

codemaker said

As from your reply, i check my BigFarm and BigBang Desktop shortcut for corruption: Right click on it > Properties, and in Target. but the target file is exactly the firefox.exe

It has this and only this:

"C:\Program Files (x86)\Mozilla Firefox\firefox.exe"

There are no "extras" that would override your start page such as:

"C:\Program Files (x86)\Mozilla Firefox\firefox.exe" "http://badsite/"

That's good.

Here's my suggested procedure for tracking down and cleaning up bad add-ons and other hijackers. I know it seems long, but it's really not that bad.

(1) Open the Windows Control Panel, Uninstall a Program.

After the list loads, click the "Installed on" column heading to group the infections, I mean, additions, by date. This can help in smoking out undisclosed bundle items that snuck in with some software you agreed to install. Be suspicious of everything you do not recognize/remember, as malware often uses important or innocent sounding names to discourage you from removing it.

Take out as much trash as possible here. If you're not sure, feel free to post program names or a screenshot of the list.

(2) Open Firefox's Add-ons page using either:

• Ctrl+Shift+a (Mac: Command+Shift+a)
• "3-bar" menu button (or Tools menu) > Add-ons
• in the Windows "Run" dialog, type or paste
  firefox.exe "about:addons"

In the left column, click Plugins. Set nonessential and unrecognized plugins to "Never Activate".

In the left column, click Extensions. Then, if in doubt, disable (or Remove, if possible) unrecognized and unwanted extensions. All extensions are optional; the troublemaker might not be obvious from its name.

Often a link will appear above at least one disabled extension to restart Firefox. You can complete your work on the tab and click one of the links as the last step.

Any improvement?

(3) You can search for remaining issues with the scanning/cleaning tools listed in our support article: Troubleshoot Firefox issues caused by malware. These on-demand scanners are free and take considerable time to run. If they finish quickly and especially if they require payment, you may have a serious infection. I suggest the specialized forums listed in the article in that case.

(4) Then double-check these settings:

* Restore your preferred home page: How to set the home page

* Restore your preferred default search engine: Change your default search settings in Firefox

Success?

Also, is your Firefox up-to-date with standard security settings? One reason there are regular Firefox updates is to close security vulnerabilities that sites might use to sneak software onto your system.