hello, you may have adware on your computer. please try these steps:

1. reset firefox (this will keep your bookmarks and passwords)
2. afterwards go to the firefox menu > addons > extensions and in case there are still extensions listed there, disable them.
3. finally run a full scan of your system with different security tools like the free version of malwarebytes and adwcleaner to make sure that adware isn't present in other places of your system as well.

Troubleshoot Firefox issues caused by malware

Sorry my original question was misleading. I am referring to unwanted sites that appear when I am browsing and click on something which then brings up the unwanted page. Seems to happen with increasing frequency. My guess would be some sort of firewall action for each url as it is discovered but have not managed to locate anything suitable. AlanB

firefox shouldn't open unwanted pages in the first place - that's why i've suspected adware plays a part in this. i still recommend performing all the steps above...

Look thru your add-ons list and make sure you know what each one is there for. Also, check the programs that are on your computer

Windows: Start > Control Panel > Uninstall Programs. Mac: Open the "Applications" folder Linux:

• Ubuntu Unity {web link}
• Xfce: Applications Menu category sections
• options depends on the package manager and the desktop environment

Go thru the list. If you find something that you don't know what it is, use a web search.

Troubleshoot Firefox Issues Caused By Malware {web link}

Do a malware check with several malware scanning programs on the Windows computer. Please scan with all programs because each program detects different malware. All these programs have free versions.

Make sure that you update each program to get the latest version of their databases before doing a scan.

• Malwarebytes' Anti-Malware:
  http://www.malwarebytes.org/mbam.php
• AdwCleaner:
  http://www.bleepingcomputer.com/download/adwcleaner/
  http://www.softpedia.com/get/Antivirus/Removal-Tools/AdwCleaner.shtml
• SuperAntispyware:
  http://www.superantispyware.com/
• Microsoft Safety Scanner:
  http://www.microsoft.com/security/scanner/en-us/default.aspx
• Windows Defender:
  http://windows.microsoft.com/en-us/windows/using-defender
• Spybot Search & Destroy:
  http://www.safer-networking.org/en/index.html
• Kasperky Free Security Scan:
  http://www.kaspersky.com/security-scan

You can also do a check for a rootkit infection with TDSSKiller.

• Anti-rootkit utility TDSSKiller:
  http://support.kaspersky.com/5350?el=88446

See also:

• "Spyware on Windows": http://kb.mozillazine.org/Popups_not_blocked

Thank you all for your replies. I feel we may be talking about different options and it is probably due to my poor explanation. My problem is when I am on certain websites, and it happens on quite a few, when I click on something within that website I am re-directed to another page, usually connected to selling something. I suspect that this is by design rather than accident and that the site owner has taken the proverbial thirteen pieces of silver. What I am basically looking for is the means to block these unwanted sites, preferably by typing their url's into an appropriate piece of software. I would have thought this was possible within Firefox, but apparently not. Does anyone know of any software that will achieve this, or is there a router on the market with this capability inbuilt? alanb7866

blocking certain urls will only deal with the symptoms - if you have adware on your computer (and when unwanted links open automatically that's a strong indication of that) it's far better to tackle it directly & remove any potentially unwanted programs!

Run most or all of the mal-ware scans on the list above.

Adblock Plus {web link} Blocks annoying video ads on YouTube, Facebook ads, banners and much more. Adblock Plus blocks all annoying ads, and supports websites by not blocking unobtrusive ads by default (configurable).

Thank you for your replies which unfortunately do not relate directly to my problem.

If you re-read my last post you will see these are not links that open automatically either due to the presence of ad or mal-ware but are the result of my clicking on an item within a web page, not quite the same thing. I believe that most if not all are due to the website owner acting in collusion with others to promote these actions, which is why I made the inference of the thirty pieces of silver.

I have both Malwarebytes and Adblock Plus together with other similar software and use them frequently. I repeat my request--does anyone know of a router or suitable software that will allow the blocking of individual url's? alanb7866.

There are viruses that will hijack your search so when you click on a link it will send you to come other website rather than your intended destination. That's why everyone is suggesting that you run comprehensive malware detection as well as closely scrutinize Firefox's configuration. Blocking specific URLs is only treating the symptoms rather than actually fixing the issue

I am guessing from the timings posted against your replies that most, if not all, of you are located on the American continent, whereas I live in UK. There is an old saying that we are two nations divided by a common language and I am starting to believe there is some truth in this. As previously stated, my browser is not being hijacked by malware or any other ware, and my paid-for anti-virus has proven itself more than capable over a number of years. My problem is simply that on some sites I am being wilfully re-directed to other unwanted pages ( I suspect with the collusion of the website owner) and I am looking to find a way to block these intruders. I had hoped that Firefox would contain such a method but apparently not, hence my request for a possible hardware solution perhaps within a particular router by posting the rogue url's as and when they appear.

To all those people who responded to my original request. I have been directed to an add-on called Blocksite which seems to press all the correct buttons. You do have to type in all the url's individually but they are then prevented from re-appearing. Exactly what I was asking for and I am a little surprised that none of you seemed to be aware of its existence. AlanB7866

You can use a router (wired or wireless) to block any website. I use a D-link wired router for this purpose. Another thing it can do is help with security.

You may also have Conduit on your system. It does a good job of hiding itself and is hard to remove. http://pcsmarties.wordpress.com/methods-to-remove-conduit/

Go to the Mozilla Add-ons Web Page {web link} (There’s a lot of good stuff here) and search for redirect blockers.

Please note the link above goes to the American page. Your local page may be different.