Yesterday evening my android phone (Google Play Services app) asked me to log in again into my account due to "security changes" (I don't remember the exact wording used).

I double checked it was the real app and logged in again (I went through all the authentication steps, including 2FA through SMS that was automatically picked up by the app).

I then checked all my account activities and security settings, and found there were no signs of access or edits other than my own. Everything looked perfectly fine, including linked devices and apps.

Should I worry, or is this a random check by Google to see if my access from the phone is still valid? (Or maybe Google Play Services just lost an auth token and asked me to log in again?)



Example of sign-in request:



Google says it's not a security problem and that you don't have to worry.
After investigation they issued a statement in the Google product forums:

What happened?
During routine maintenance [from 1pm to midnight PST yesterday], a number of users were signed-out from their Google accounts. This may have resulted in you being signed out of your account or seeing a notification about “A change in your Google account” or “Account Action Required.”
We hear your concerns that this appeared to potentially be phishing or another type of security issue. We can assure you that the security of your account was never in danger as a result of this issue. You can always learn more about the Security tools Google provides at www.google.com/safetycenter/
What should I do now?
First, try signing back in with your usual username and password at accounts.google.com. If you can’t remember your password or can’t sign in for another reason, recover your account here: g.co/recover.

Note that the statement only refers to this particular incident from around February 24th, 2017 which has affected many users and is likely harmless. But more generally, if Google is asking for a security confirmation or warning you about changed account details, you should take that seriously and review your security settings and recent logins - as you should do regularly anyways.
