NATO and the EU must respond in kind. Immediately cut all hard-line Internet connections in and out of Russia, and block Russian IPs using wireless or satellite communications. Extend that response to any country that aids Russia by sharing their pipeline.
That would end the hacking, the ransomware attacks, the honeypots and compromising attacks, the disinformation, the election interference, the attacks on infrastructure, and more. Obviously they'd still find a way to get information through at a trickle, but good luck with that.