06-04-2019 02:04 AM - edited 06-04-2019 02:06 AM
Killing processes one by one in Task Manager confirms your first hypothesis. The popup appears to come from Windows Update. Further research suggests that MS may be pushing an Intel microcode patch:
However, I have not received any of the expected notifications from either Windows Update or Security Center. According to https://portal.msrc.microsoft.com/en-us/security-guidance/advisory/adv190013 (which I found through the above page), the relevant OS update appears to be https://support.microsoft.com/en-us/help/4499165/windows-8-1-update-kb4499165, which I installed on May 19th. Generally, the MS pages refer one (as I would expect) to the manufacturer for firmware updates. For example, the
06-14-2019 08:51 AM - edited 06-14-2019 08:51 AM
A little digging around turned up these events:
So it appears to be an update to Battery Firmware, not BIOS or TPM.
Why should this come unannounced via Windows Update, instead of via Lenovo's System Update?
Why are there no indications of this update in the Windows Update GUI or in WindowsUpdate.log?