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How do I stop the "Ads not by this site" on every Firefox web page?

  • 4 replies
  • 130 have this problem
  • 11 views
  • Last reply by Neilfox

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An advertisement appears on the to of the majority of web pages. It is always accompanied by the words "Ads not by this site". In some cases the area consumed by this add removes data from the bottom of the page and can not be recovered. This "feature" has appeared two days ago and I have tied, without success, to disable it.

An advertisement appears on the to of the majority of web pages. It is always accompanied by the words "Ads not by this site". In some cases the area consumed by this add removes data from the bottom of the page and can not be recovered. This "feature" has appeared two days ago and I have tied, without success, to disable it.

Chosen solution

Check the connection settings.

If you do not need to use a proxy to connect to internet then try to select "No Proxy" if "Use the system proxy settings" or one of the others do not work properly.

See "Firefox connection settings":


Do a malware check with some malware scanning programs on the Windows computer.
Please scan with all programs because each program detects different malware.

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

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

See also:

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All Replies (4)

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Chosen Solution

Check the connection settings.

If you do not need to use a proxy to connect to internet then try to select "No Proxy" if "Use the system proxy settings" or one of the others do not work properly.

See "Firefox connection settings":


Do a malware check with some malware scanning programs on the Windows computer.
Please scan with all programs because each program detects different malware.

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

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

See also:

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Sounds like some sort of adware, probably something installed globally or it is malware.

It is not a Firefox feature. This sort of software may be difficult to track down as some people may well install it intentionally and it may not be classified as malware by anti malware tools.

A screenshot may help and can be attached to your post by using the add images [Browse...] button


Sometimes a problem with Firefox may be a result of malware installed on your computer, that you may not be aware of.

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

Microsoft Security Essentials is a good permanent antivirus for Windows 7/Vista/XP if you don't already have one.


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

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

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Morning cor-el,

Thanks for your input, I ran msert and it found and removed 4 suspect items. All is well again.

Thanks Merty

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Uninstall extensions called Adlycris, LyricsSay and SeeSimilar. These extensions display "ads not by this site ads", learn more:

http://deletemalware.blogspot.com/2013/01/remove-ads-not-by-this-site.html

Then run Malwarebytes and AdwCleaner. Avast browser clean up tool may help as well.