System-wide Ad Blocker

I intend to build an Ad Blocker application that blocks ads on all browsers. Some Ad Blockers have plugins for each browser, but I think that's a lot of work and incompatibilities. I'm thinking on an application that works like a firewall for ads. The开发者_Python百科 main OS is Windows, of course.

Is possible to write something that works on all Windows versions (2000, XP, VISTA, 7) ? What is the best approach for this kind of software ?

Some VPN's have a system-wide ad-blocking system.

Private Internet Access and NordVPN both have an integrated ad-blocking system. This means even when you use various browsers or applications which connect to the internet, you can block ads. Both are integrated differently though because PIA works flawlessly. NordVPN does not work as well, sometimes it blocks ads, sometimes not. They claim to block malware and trackers too.

you can not do so dynamically, because every popup is instance of your browser and calls to ad url, so system can not differentiate if you make call or popup

Technically it is possible to do this by filtering packets in a manner similar to a firewall, but it is much harder to do and not as elegant. The biggest problem is that you have to reassemble HTTP responses into HTML documents and parse them yourself. Then you have to strip out the elements that display ads or popups, reassemble the HTTP response, and send it back out to the destination (e.g. the browser). If you are running in the browser you get the HTML document assembly for free and don't have to worry about network traffic at the packet level. Also, in the browser you can have UI elements (toolbar, configuration/statistics dialog, etc). We actually do ad filtering at the packet level in our current product; trust me - it sucks.