"Cyber warfare" is an overrated idea.
The idea of "penetrating" important networks over the internet sounds cool but is fundamentally flawed: You don't hook up important networks to the internet unless you're a complete idiot.
Also commonly forgotten/ignored/not known is that hacking isn't magic. Hacking takes advantage of flaws or bugs in software, or in people. Virtually all systems that get hacked, get hacked because of bugs that have been known and fixed for some time, when the admin simply didn't update it. Anything even semi-important should be fixed quickly.
Keeping important systems safe isn't a whole lot of work. The biggest threat wouldnt be internet geeks, but would be intelligence agents using social-engineering to gain access.