Microsoft Azure AD Connect Agent Updater unannounced and unplanned server restart

I’m writing today to share about an experience I had hours ago, where the Microsoft Azure AD Connect software (specifically the Azure AD Connect Agent Updater) actually updated itself, and restarted the server it’s installed on, all during production hours.

Pretty serious stuff hey?

It all happened around 12:50PM (Mountain Time)… I received a notification that a service had been marked as failed on the particular server (notification from my monitoring/management system), and I went to investigate. I noticed that the server was actually gracefully restarted. After logging in, I came across these event logs.

Both Event ID 34004 and Event ID 1074 were logged, reporting both that it had downloaded an update, installed, and the installer initiated a restart.

I thought: no way should auto-updating be enabled, and I still can’t actually confirm it either. I found this article which explains of an automatic update feature:

https://docs.microsoft.com/en-us/azure/active-directory/connect/active-directory-aadconnect-feature-automatic-upgrade

However, not only did I not meet the criteria of auto-update being enabled, but upon further investigation it was actually disabled by running the powershell command:

Get-ADSyncAutoUpgrade

As you can see below the command returned as “suspended”.

After spending tons more time searching and not finding anything, I decided I’d just disable the service called “Microsoft Azure AD Connect Agent Updater”. In my environment it was running and set to “Automatic (Delayed)”, but I stopped the service and changed it to “Disabled”.

It’s not reflected in the picture below, but this is the service that was responsable for updating and restarting the server. Since I’ve stopped it, it appears everything is functioning correctly, except auto-updating.