I don't think massive is quite the right word here even if it affected many government departments. I haven't heard any new of this being anything more than disruptive, so it seems more like a shot across the bow. Maybe it was a complex hack and a way to say look at our capabilities. If you see a hack that cripples any infrastructure or one the has severe economic implications you will know the situation is out of control.

Honestly I didn't think it would go this far so I'm not sure where we go. I would have seriously bet that Russia would just have continued posturing rather than actually taking any direct action, to draw the west into making the first move.