Microsoft confirmed Wednesday that a suspicious-looking update pushed out to Windows machines globally in the early hours was nothing more than a test gone errant.
A spokesperson said that the company had "incorrectly published a test update" and is in the process of removing it.
It follows an hour or two of brewing concern on social media, forums, and news-sharing sites that the Windows Update service had been compromised in some way.
The "important"-rated patch, appeared on Wednesday as a supplemental language update, rather than a security fix.