CERT, the government-funded Internet security group, was knocked off the Web yesterday morning in the US after it came under attack for the second time in three days.
"We are under attack again," said Bill Pollak, spokesman for the CERT Coordination Center at Carnegie Mellon University in Pittsburgh. "We're not saying too much more about it than that."
This is the second major attack launched against the organisation that's known as a purveyor and champion of Web security. On Tuesday, a distributed denial-of-service attack was launched against the site. It disrupted service but didn't shut the site down. CERT hasn't said if this new attack is related to the previous incident.
In response to Tuesday's attack, the organisation posted a warning on its site that some services might be disrupted and asked anyone reporting an emergency to call the CERT Coordination Center hotline. For non-emergencies, CERT asked that people send e-mails to email@example.com.
CERT officials said the site is attacked almost every day, but added that it had never been hit by such a disruptive attack before.
Officials at CERT have remained silent about what measures they are taking to combat the attacks and find out who might be responsible.