Windows itself does not, 3rd party firewall/HIDS software (ZoneAlarm, Outpost, etc) for Windows has done this by intercepting APIs to do things like call executables with internet access, OpenProcess calls, raw disk IO, registry writes to startup entries, etc.

I'm not sure what they are talking about, but windows comes with a built-in sandbox now. Adds a little bit of overhead, but besides that works very well.

I guess one might try to check the path through the process tree to see if a blacklisted application is the parent (or gp, ggp, etc.) of the process trying to communicate with the outside world.

I considered that but IIRC browsers like firefox will accept to load an URL without creating a new child process.

For instance if I type "firefox 'http://google.com'" in my terminal my already-running firefox instance loads the URL in a new tab, so I assume that some kind of IPC is used behind the scenes to ask the main instance to load the URL. Of course that's harder to exploit nefariously than spawning wget from the same process but when there's a will there's a way...