Wow, one wonders why someone might leave a review in RUSSIAN spreading such outrageous disinformation... So you do realise that web extensions have no access to the operating system and operate strictly within the browser process! It is not possible for an extension to do what you claim, and if anyone wants to verify this well feel free to go through the code - it's open source!

https://github.com/xbrowsersync/app

Did make me chuckle though!