Because the worm is programmed to attack only that address and not the site that it redirects to, the software giant has decided to eliminate the Windowsupdate.com address.
The move is one of a series of efforts that Microsoft has undertaken to try to thwart an attack on its servers that was expected to be launched by infected computers starting on Friday.
"One strategy for cushioning the blow was to extinguish the Windowsupdate.com" site, said Microsoft spokesman Sean Sundwall. "We have no plans to ever restore that to be an active site."
On Thursday, Microsoft changed the Internet addresses that correspond to the Windowsupdate.com entry in the domain name service (DNS) servers that act as the Internet's address book. One source familiar with the change said that the new addresses are no longer on the same network as Microsoft's other servers, thereby insulating the company's servers from any attack aimed at Windowsupdate.com.
Sundwall stressed that the Windows Update service remains up and running, noting that the service never connected to Windowsupdate.com. Access to Windows Update is built into the latest versions of Microsoft's Windows client and server operating systems.
To get the latest patches, consumers can type in windowsupdate.microsoft.com or, as Microsoft would prefer, go to the main Microsoft.com page, where they can find information on downloading patches as well as on setting up a firewall and installing antivirus software.
The worm is programmed to start attacking Windowsupdate.com at midnight Friday in each time zone. As a result, Australia was among the first countries slated to be affected, with its midnight hitting at 7 a.m. PDT.
Even as Microsoft battles the MSBlast worm, the company was hit late Thursday with a separate denial-of-service attack on its main Microsoft.com site. The site was largely inaccessible for about four hours, beginning at 9 p.m. PDT Thursday.
The company does not know the origin of the outage but said it stemmed from a denial-of-service attack unrelated to the MSBlast worm. Sundwall said Microsoft has "every confidence that it had nothing to do with 'Blaster,'" as the worm is also known.
CNET News.com's Robert Lemos contributed to this report.
