MSBlast worm outbreak 'infected 8 million PCs'
New data from Microsoft suggests that at least eight million Windows computers have been infected by the MSBlast, or Blaster, worm since last August - many times more than previously thought. The latest data comes from the software giant's ability to track the usage of an online tool that its engineers created to clean systems infected with the worm. Since the January release of the tool, more than 16 million of the systems that connected to Microsoft's Windows Update service were found to be infected with MSBlast and were offered a patch and the use of the disinfecting tool, the software giant told silicon.com's sister site CNET News.com. During the same period, about eight million systems actually called on Update to patch them and prevent reinfection and used the special tool to remove the worm.
Though Microsoft believes the total number of users infected by the worm is likely closer to the higher, 16 million tally, the eight million figure may provide a more solid indication of the minimum number of systems hit. The larger number may include systems counted more than once, as busy computers users declined to deal with the worm immediately, or cancelled the process once it had begun, only to return to Windows Update later. Once those systems were disinfected and patched, however, they would not be re-counted. Microsoft did not track what systems, specifically, used the tool, just that it was used.
