On March 31, 2017, Microsoft released a security update for Windows Defender and Microsoft Security Essentials. The update inadvertently flags the common system OCX file “sysinfo.ocx” as infected by the virus Worm:Win32/Bluber.A. This is a false positive, and Microsoft has subsequently released a fix for the update.
To fix the error, please follow these instructions:
1) Open Windows Defender (or Microsoft Security Essentials, depending on your operating system)
2) Click on the History tab
3) Find the quarantined file “Worm:Win32/Bluber.A” and check the box, and click “RESTORE”
4) Click on the Update tab, and select the Update button to download the latest release of Windows Defender or Microsoft Security Essentials
To perform a manual update, download the latest release here:
Malware Protection Center
NOTE: If you are using Endpoint Protection, please perform a virus definition update, and restore the quarantined file.
For more information about the false positive issue, read this article on The Register.