Ultra Popup Blocker (or UPB for short) is a lightweight Popup Blocker that aims to radically block all popup windows by default, (even good, unharmful, user-initiated ones) while giving users control to allow popups temporarily or permanently via a whitelisting mechanism.
Built-in Firefox and Chrome popup blockers blocks only the popups that were created automatically via script on page load etc. When you click on a button on the page, it won't block it.
However, malicious websites can create JS code that will launch the popups whenever you click on any blank space on the page for instance.
Here, we override 'window.open' with our own implementation which prompts the user to see whether he really wants to open a popup window.
Use the dynamic list provided with Ultra Popup Blocker to manage which websites are allowed to open popups freely.