Europe is getting hit by another massive cyberattack

Andrew Roth, reporting for the Washington Post:

A new wave of powerful cyberattacks hit Europe on Tuesday in a possible reprise of a widespread ransomware assault in May that affected 150 countries, as Ukraine reported ransom demands targeting the government and key infrastructure, and the Danish Maersk conglomerate said many of its systems were down.

These attacks are getting more sophisticated and are targeting major country's key infrastructures. At what point do countries like the Ukraine, which has been hit multiple times now, have to start treating these attacks as an act of war?