I have the same problem.
I was able to prevent the app from opening a link by not allowing it to spawn a browser process. That worked for a while, then suddenly stopped working. I was able to fix it with some combination of deleting the rule and rewriting it, and/or shutting down emsisoft and restarting it, and/or rebooting. I don't recall exactly what I did, but it worked.
The rule has stopped working again, and none of the above fixes it. Everything is blocked on the executable, and it is still able to open a browser.