More than 100 companies have been hit by computer viruses that exploit a recently found loophole in Windows.
Heavy equipment maker Caterpillar was hit by the bugs
The New York Times, CNN, ABC News and heavy plant maker Caterpillar all had computer problems caused by a family of malicious worms.
Virus writers have reacted very swiftly to abuse the vulnerability which Microsoft revealed barely a week ago.
Despite the high-profile victims, security firms said they expected damage to be limited.
On 9 August, Microsoft released critical security advisory MS05-039 which revealed a vulnerability in the Plug-and-Play component of Windows 2000. Code to patch the loophole was also made available.
Plug-and-Play is intended to make it easy to connect new devices to Windows machines.
Barely five days after the Microsoft warning, a worm called Zotob appeared that exploited the loophole. Now there are nine viruses, some variants of the Zotob worm, that exploit the bug in a variety of ways.
"We are seeing the time lessen between vulnerability and exploit," said Sal Viveros, security expert at McAfee. "It used to take months."
The family of bugs seems to have caught out several US companies including many media firms.
In the UK the Financial Times was struck. A Microsoft spokeswoman said a "fairly small" number of users had been affected.
Research firm AssetMetrix reports that Windows 2000 is still the most dominant version of Windows used in large firms. More than 50% of desktops in companies with more than 250 computers run the program.
Net monitoring firm Netcraft said the worms were having no effect on the websites of large firms that run on Windows 2000.
Only users of Microsoft Windows 2000 operating system are likely to be vulnerable to the family of bugs.
Users will know if they have been caught out by the worm as their computer will continually restart. Mr Viveros said this was in contrast to many other worms which can infect computers often without their owner's knowledge.
As a worm the bug can travel by itself around the net searching for new victims. Other versions of Windows can act as carriers but will not continually re-boot.
Security firms said the best way to protect against the bug is to download and apply Microsoft's patch.