How can I remove unwanted ads on top of sites? [duplicate]

I'm running Windows 7. Yesterday, when I opened a website with Firefox, I saw 3 ads at the top of the site.

Then, when I checked other websites with different browsers, I saw these ads:

enter image description here

In the page source, I can't see any code for these ads. After using Inspect Element, this code was added to the header:

<iframe src="http://85.25.138.211/index.php?3a2j"></iframe>

And the code in the body for this ad is:

<a href="http://track.impreskin.pl/product/ImpreSkin/?uid=21002&amp;pid=153&amp;bid=1659" rel="nofollow" title="wygladzanie zmarszczek"><img src="http://track.impreskin.pl/banner/?uid=21002&amp;pid=153&amp;bid=1659" alt="wygladzanie zmarszczek"></a>

I don't see any new and unwanted plugins in my browsers, and I haven't installed Hotspot Shield.

Is this malware, and if so, how can I remove it?


You are experiencing malware which has been designed to operate just before your web browser displays web pages. It typically intercepts a browser request to retrieve a web page, analyzes the site you are visiting and tries to inject HTML ADs which may or may not be pertinent to what you are viewing.

You will have to check the proxy settings of all of your web browsers and run full malware and antivirus scans on your PC because your computer is severely infected

Adblock will not help you, this is a virus. I would confidently guess that all web pages are loading very slowly and if you check your task manager then FireFox is probably using 300-500 MB just to view one website.


After research I found this answer by Martin Prikryl:

... the problem is happening on cellular network only because of caching. After some time of being connected on cellular network and keeping refreshing, the problem went away. And reappeared only after connecting back to the Wi-Fi.

This made it obvious that the problem is due to compromised router. Resetting it back to factory settings fixed it.