Ask HN: Google account on old yahoo.com email hijacked to Google Workspace

Overnight, I received dozens of emails from Google Payments (noreply@google.com) notifying me that contact emails are being changed on a Payments profile that either I never created or is extremely old. These are actual Google notifications, not phishing attempts.

It started with my actual old email address (a Yahoo address I've had for 20+ years) being swapped out to a gtempaccount.com addresss, which appears to be the attacker moving the account into a Google Workspace.

How they did this for a yahoo.com email address without my approval is not clear, but I am 99% sure my Yahoo email is secure. I have taken the standard precautions anyway (changed password, confirmed 2FA which is already enabled)

Since then I've received a flood of similar notifications with different email addresses cycling through the same profile.

I can still log into my original account but it shows as the "@gtempaccount.com" suffix, and there doesn't seem to be anything useful I can do within the account.

Despite extensive searching and chatting with Google's support bots, there is no clear place to report this issue.

Any suggestions as to where this can actually be reported or other actions to take are very welcome.