I know this is an old question but I want to share some tips that help get rid of such browser hijackers or unwanted programs.
If you are seeing pop-ups or linked to a specific site, they are almost certainly being caused by malware. Here are some tips you can follow:
Uninstall unfamiliar or suspicious extensions.
Uninstall suspicious programs from your computer.
Reset your browser settings.
It's also necessary to check your browser's shortcut and make sure it's been affected.
Take Chrome for example (mentioned in this article:
http://www.okpckit.com/how-to-remove-nova-rambler-ru-from-iechromefirefox/ which I found by chance on the net a few days ago)
Find Chrome icon on desktop, right click it first, and then select “properties” option from the drop-down list.
Once the new window is opened, check “target” section and delete the malicious argument if it is added after “C:\Program Files\Google\Chrome\Application\chrome.exe”. “C:\Program Files\Google\Chrome\Application\chrome.exe” should be left only. Check it again, click “OK” as it is clear.
If necessary, try Adwcleaner or Malwarebytes Antimalware.
Hope this helps.