Several new computer worms were being blamed for causing computer system disruptions at some media outlets and companies in the US yesterday.
The worms, including two called IRCBOT.WORM and RBOT.CBQ, exploit a recently discovered flaw in Microsoft's Windows 2000 operating system, and caused personal computers at more than 100 US companies to restart repeatedly and potentially exposed them to attackers who could take control of a system.
This is the most significant threat we've seen in at least 12 months,'' said Vincent Gullotto, vice president of the anti-virus emergency response team at McAfee. But Symantec and McAfee, the top two computer security companies, as well as Microsoft, said that damage to computer systems on Tuesday was limited and was not likely to cause widespread havoc like other malicious software programs such as SQL Slammer and MyDoom.
CNN, breaking into regular programming, reported on air that personal computers at the cable news network were affected by a worm that caused them to restart repeatedly. The New York Times and ABC News also reported problems earlier on Tuesday, causing some to suspect that another recent worm called Zotob was behind Tuesday's outages.
Gullotto said, however, that the newly discovered worms were different from Zotob, even though they all, including Zotob, appeared to exploit the same vulnerability in the Plug-and-Play feature in Windows 2000, which runs on less than half of the world's personal computers.
Microsoft, which warned users last week of three newly found critical security flaws in its software, urged users to update the software on their personal computers to prevent them from being infected.
