Microsoft's own investigation on the other hand revealed malware is likely to blame for the freezing issues, the company claims it found no evidence that its November Security Updates make changes to the system that can cause these issues. Prevx backtracked and now also believes malware is to blame, the company offered its apologies for the stir that their initial report may have caused.
"We’ve conducted a comprehensive review of the November Security Updates, the Windows Malicious Software Removal Tool, and the non-security updates we released through Windows Update in November. That investigation has shown that none of these updates make any changes to the permissions in the registry. Thus, we don’t believe the updates are related to the “black screen” behaviour described in these reports."
"However, we do know that “black screen” behaviour is associated with some malware families such as Daonol," it adds.