The company, known for its claim of ownership on critical pieces of code that make up the Linux operating system, said the attack started Wednesday at 3:20 a.m. PST and continues to block access to the site.
"A bunch of servers (on the Internet) are compromised," said Blake Stowell, a spokesman for the Lindon, Utah-based company. "Those servers are all turned to fire on the SCO Web site."
In August, hackers downed the Web site for almost three days. Another attack in May made the Web site inaccessible for several hours.
"If it is anything like past attacks, it will probably be resolved in about 24 hours or so," Stowell said. Without access to the company's Web site, customers may not be able to get timely updates and patches, he added.
The attack comes as the company continues to receive criticism for its pursuit of a legal case that, if successful, would turn over ownership of critical parts of the Linux source code to SCO.
However, critics won a tactical victory Friday, when a judge gave SCO a month to show the portions of the Linux software it believes it owns and to point out where it believes IBM and others are infringing.
The case hasn't tamed the growth of Linux sales. A recent report published by market researcher IDC found that sales of Linux servers grew almost 50 percent in the third quarter of 2003 compared with the same period a year earlier.
