The SCO Group set up a temporary website yesterday, a day after the MyDoom computer worm knocked the US software company's website offline.
SCO, which is offering a $250,000 (€201,300) reward for information on the worm's creator, directed customers and vendors to the new website, and said it expected the denial of service attacks to continue until February 12th.
A separate $250,000 reward is being offered by Microsoft, which is expected to become a victim of the worm later today.
Microsoft said at the weekend it had been preparing for an attack from a second variant of the computer worm, MyDoom.B.
Both the MyDoom worms are programmed to take over a computer and use it as a launching pad to send a huge barrage of data requests to the firm's sites.This type of denial of service attack effectively paralyses websites, making them inoperable.
Security experts are more confident Microsoft.com will withstand the attack as it's considered one of the most stable sites on the internet. "With such a program you could really take out any major website on the internet," said Mr Raimund Genes, European president of security software firm Trend Micro. "This is a form of electronic warfare. It's not terrorism but it is somebody who is obviously upset with SCO."
Utah-based SCO has drawn the ire of advocates of the Linux computer operating system, which is a rival to SCO's Unix and Microsoft's windows. Linux was developed by volunteer programmers and can be downloaded for free. Linux advocates object to SCO's attempts to collect licence fees for the freely available software.
