McAfee update cripples Windows XP machines

McAfee has apologised to its customers after a routine security update crippled Windows XP PCs.

The update falsely identified the SVCHOST.EXE Windows file as a virus, effectively prompting the McAfee software to attack core operating system files. This causes affected PCs to crash or enter endless reboot cycles.

The problem appears only to have affected McAfee customers running Windows XP SP3, but it has reportedly downed tens of thousands of PCs across the world, including those of Intel, US police departments and universities.

Today we released a update file that clearly did more harm than good

McAfee claims businesses are worse hit than consumers, although it’s playing down the impact of the false positive. "We believe that this incident has impacted less than one half of one percent of our enterprise accounts globally and a fraction of that within the consumer base – home users of products such as McAfee VirusScan Plus, McAfee Internet Security Suite and McAfee Total Protection," writes Barry McPherson, the company’s executive vice president for customer service on the McAfee blog. "That said, if you’re one of those impacted, this is a significant event for you and we understand that."

McAfee has halted distribution of the flawed update an issued a fix for the problem.

In a follow-up blog post, McPherson admitted the company had let its customers down. "In our ongoing efforts to protect our customers from a seemingly endlessly multiplying variety and volume of attacks, today we released a update file that clearly did more harm than good," he said. "There was a legitimate threat and we wanted to protect our customers, as we have done successfully thousands and thousands of times before. But in trying to do so, we created negative and unintended consequences for some very important people. Many of you."

"Mistakes happen. No excuses," McPherson added. "The nearly 7,000 employees of McAfee are focused right now on two things, in this order. First, help our customers who have been affected by this issue get back to business as usual. And second, once that is done, make sure we put the processes in place so this never happens again."