US and South Korean websites flooded by a continuous wave of cyber-attacks

US and South Korean web sites have been the target of a wave of ongoing cyber-attacks snce 4 July, which is still continuing, leaving investigators in both countries baffled on the reason behind what they describe as unsophisticated denial-of-service attacks.

The cyber-attacks had initially targeted US and South Korean government agency websites, which later spread to commercial websites. In all, 27 websites have been brought under attack in both countries.

US investigators and cyber experts say the nature of the attacks have been relatively unsophisticated, with one expert calling it the "garden variety", which could not have been carried out by professional hackers.

The attacks, with the help of 50,000 to 65,000 computers had been directed to flood a particular website with repeated access requests, causing the network to slow or shut down.

Experts say that that the attack, using robotic networks, or botnets, (a network of a million or more compromised PCs) involving 50,000 to 65,000 computers, delivered the MyDoom worm, a malware, which came on the scene in 2004, and since then appearing in numerous variants like the Mytob virus to these computers.

The elementary nature of the cyber-attack, which had taken the US and South Korea off-guard, has led many experts to believe that the attacks were carried out by hackers more for publicity and glory among their peer group, since the targets were high profile government and internationally reknowned company sites.