Days after systematic cyber attacks against government and financial institutions crippled computer networks in South Korea and the United States, additional cyber attacks have hit both nations.

Unlike the first wave of attacks earlier in the week, the U.S. State Department said its networks are still being targeted, but with lower volumes of attacks.  South Korean officials said some of its government networks are still being targeted, but also have noticed a dramatic decline in the attacks following July 4.

The botnet had at least 100,000 hijacked computers in South Korea, Japan, China, the U.S. and other countries, which makes accurately tracing the source of the attacks extremely difficult.

"The anticipated attack did take place, but considerable countermeasures were taken and it did act as a defense to some degree," an Ahnlab security firm official told Reuters.  Ahnlab also pointed out that "tens of thousands" of affected computers could have problems booting up, although other experts have not been able to verify that number.

Several U.S. federal agencies will now monitor popular online hacker hideouts, while security experts attempt to locate any digital fingerprints left behind in computer code.  The group responsible appears to be rather unorganized and possibly inexperienced, causing experts to note how a larger, more organized group may be able to cause a higher level of cyber damage to targets.

Security experts are now trying to figure out who is behind the cyber attacks, though early reports indicate North Korea may be behind the attacks.  China and North Korea were both immediately suspected of the attacks, but Chinese officials denied the accusations, saying there was no reason for them to launch so many attacks against South Korea.

The country, unlike China and other regions in Eastern Europe, reportedly have not launched organized cyber attacks, but this could mark its entrance into cyber warfare.

Moving forward, security experts are concerned the cyber attacks could spread from major computer networks to individual PCs, with hackers possibly hijacking them, then turning them into zombies.  If this truly is a cyber war, it appears there is very little the U.S. and South Korea can do against the perpetrators -- assuming they're accurately identified in the first place -- leading to other attacks from the same group.