Internet security experts warned of the possibility of a wave of cyberattacks this weekend in a hacker contest that could lead to the disruption of many computer networks.
The so-called "Defacer's Challenge," scheduled for tomorrow, aims to deface up to 6,000 Web sites over the course of six hours, according to security experts.
"While there is no guarantee that this event will actually take place, the possibility is reason enough to verify your security and patch readiness," Counterpane Internet Security said in a message to clients.
Another firm, Internet Security Systems (ISS), made a similar announcement and raised its warning level to 2 on a scale of 1 to 4, suggesting increased vigilance.
ISS analysts "are in the process of monitoring the hacking challenge in order to determine the effect the competition may have on the Internet," the company said.
The US Department of Homeland Security, however, played down the threat, saying it has issued no new warning on the matter.
"Hacker contests are relatively common, so I'm a little mystified why this is receiving so much attention," said agency spokesman David Wray.
While the agency has notified corporate chief information officers, Wray said, "We have not put out any public warning on this."