Some people still using WSUS and you might see three mysterious updates, KB4078126, KB4078127 & KB4078128, all of them are dynamic updates and they are labeled as “TEST ONLY – DO NOT USE”. 

kb4078126-und-kb4078127

It’s unclear why Microsoft released test updates into WSU, it could be an accident or for a reason. I suggest you ignore those updates because via the normal update catalog or the Windows update mechanism all of the three updates are not visible.

[gallery ids=”2731,2732” type=”slideshow” orderby=”rand”]

Theoretically, it could be the new microcode update which Intel announced recently but it’s all guessing but it would make sense since these updates are ‘critical’ ones.

Source