An update in the popular Antivirus, McAfee, is causing Windows Xp to reboot continuously. So, far it has been reported that the problem is only with the McAfee corporate customers.
The update, identified as DAT update 5958, identifies svhost.exe as a threat and deletes it. This results in the machine rebooting continuously.
McAfee has confirmed the problem and removed the faulty update. They have also offered a fix for the problem. We do not have a Windows Xp system and could not test the fix.
This is what McAfee has to say to Engadget:
McAfee is aware that a number of customers have incurred a false positive error due to incorrect malware alerts on Wednesday, April 21. The problem occurs with the 5958 virus definition file (DAT) that was released on April 21 at 2.00 PM GMT+1 (6am Pacific Time).
McAfee teams are working with the highest priority to support impacted customers and plan to provide an update virus definition file shortly. McAfee apologizes for any inconvenience to our customers.
Our initial investigation indicates that the error can result in moderate to significant performance issues on systems running Windows XP Service Pack 3.
The faulty update has been removed from McAfee download servers for corporate users, preventing any further impact on those customers. We are not aware of significant impact on consumer customers and believe we have effectively limited such occurrence.
While McAfee have confirmed that the problem do exist, it is certainly a outrageous claim from McAfee to say that deleting svhost.exe results in a "moderate to significant" performance loss, afterall svhost.exe is a very important process for the proper functioning of a Windows system.
As of now the McAfee forums is also down (possibly due to the people trying to get in due to the problem) and there is no way of providing an estimate the number of affected users. However, we expect the number of affected machines to be huge.