No lights, no heat, no money - that's life in Ukraine during cyber warfare

Hackers who defaced and interrupted access to numerous Ukrainian government websites on Friday could be setting the stage for more serious cyberattacks that would disrupt the lives of ordinary Ukrainians, experts said.

"As tensions grow, we can expect more aggressive cyber activity in Ukraine and potentially elsewhere," said John Hultquist, an intelligence analyst at US cybersecurity company Mandiant, possibly including "destructive attacks that target critical infrastructure."