BBC Saturday, 25 January, 2003, 12:14 GMT
Virus-like attack hits web traffic
The attack targeted Mircrosoft database software
Traffic has slowed dramatically on many parts of the internet - apparently the result of a fast-spreading, virus-like infection, computer experts say.
The electronic attack is reported to have interfered with web browsing and e-mail delivery.
Experts said the attack on Saturday was similar to the impact of the "Code Red" virus, which brought internet traffic to a standstill in the summer of 2001.
"It's not debilitating," said Howard Schmidt, one of President George W Bush's top cyber-security advisers, quoted by the Associated Press news agency.
"Everybody seems to be getting it under control."
South Korea hit
He said the FBI's National Infrastructure Protection Center and private experts at the CERT Co-ordination Center were monitoring the attacks.
It is highly likely hackers have launched an all-out attack on the country's internet system
In South Korea internet services were shut down nationwide for hours on Saturday, the country's Yonhap news agency reported.
It said the shutdown was triggered by "apparent cyber terror committed by hackers".
It was not immediately clear if the South Korean attack was the same as that reported in the United States.
It is the first time South Korea's wired and mobile internet services have been hit collectively in such a way, according to Yonhap.
But the impact on most financial institutions, corporations and government offices was minimal as they were closed for the weekend, it said.
According to software experts quoted by AP, the attack targeted vulnerable computers, infecting database software from Microsoft Corp., called "SQL Server".
The attacking software code overwhelmed many internet data pipelines as it searched for victim computers randomly and aggressively.