U.S. warns of large-scale virus attack

U.S. warns of large-scale virus attack

Chicago — U.S. government and industry experts warned late Thursday of a mysterious, large-scale Internet attack against thousands of popular websites.

The virus-like infection tries to implant hacker software onto the computers of all website visitors.

Industry experts and the Homeland Security Department were studying the infection to determine how it spreads across websites and find adequate defences against it.

"Users should be aware that any website, even those that may be trusted by the user, may be affected by this activity and thus contain potentially malicious code," the government warned in one Internet alert.

The mysterious infection appeared to target at least one recent version of software by Microsoft Corp. to operate websites, called its Internet Information Server, popular among businesses and organizations.

A spokesman for Microsoft declined comment immediately.

Experts said the attack's effects were unusually broad but weren't substantially interfering with Internet traffic.

"While this is significant, it has no impact on the operation of the Internet," said Marcus Sachs, who helps run the industry's Internet Storm Centre in Bethesda, Md.

Experts urgently recommended consumers and corporate employees update antivirus software on their computers, since the latest versions can immunize visitors to infected websites.

The infected websites attempt to implant on visitors' computers hacker software that allows others to use their computers to surreptitiously route Internet spam e-mails.