The "Code Red" computer virus reached Switzerland early this morning infecting numerous well-known companies, a Swiss government spokesman said.
Meantime the FBI said early this morning that over one million US computer users had downloaded a protective patch to avoid attack by the bug, which was programmed to attack the internet in North America after 8.00 p.m. Eastern Standard Time (1.00 a.m. Irish time today).
At least 10 webservers in Switzerland and their homepages were infected by Code Red, according to Mr Claudio Frigerio from the Federal Office of Information and Telecommunications.
He said it had attacked internet addresses using the suffix ".ch". The worm also tried to infiltrate the Swiss government's system but did not get past an anti-virus system.
The FBI said it was "on full alert to follow progress of the worm throughout the night." All of several US government and business websites accessed by the Irish Times an hour after the deadline were working normally.
It may be 36 hours, however, before what Mr Chris Rouland, of Internet Security Systems of Atlanta, described as possible "massive degradation of bandwidth on the internet" resulting from the worm occurs.
"Code Red" infected 345,000 servers two weeks ago and is programmed to start spreading again from July 31st. The address www.whitehouse.gov - the website address for the White House - is designed to be attacked on the 20th of every month from PCs where it lies undetected. The White House has moved its website since the first assault on July 20th.
The worm is expected to replicate throughout the internet for the next 19 days, disrupting business and trade on a global scale and posing potential dangers to international security, officials said.
The internet system could be overwhelmed as the bug floods cyberspace looking for computers to attack.
Users of business software applications were taking the warnings of internet chaos seriously, despite lingering scepticism over such scares since the much-hyped Y2K computer glitch failed to cause widely forecast disruption on January 1st, 2000.
A simple patch downloaded from the Microsoft website could provide adequate protection, Microsoft officials said. Mr Scott Culp, Microsoft's security-program manager, said several hundred thousand copies of the patch had been downloaded since the problem was disclosed on July 18th, and that a single copy could be used to fix thousands of servers across a single corporation.
Without the patch, the bug could replicate itself rapidly from vulnerable links and cripple the internet, warned Mr Rouland at a Washington press conference on Monday. The worm can also be purged by switching the computer off and re-booting it.
"Code Red" infects Microsoft's Windows 2000 and Windows NT and its popular Internet Information Server. Cisco Systems 600-series DSL routers could also be affected.
