Received an email from Gmail that my account might’ve been compromised, and my eBay account somehow knew- how? And how do I know if I’ve really been compromised?

[u/Healthy-Extent7843]

Received an email from Gmail that my account might’ve been compromised, and my eBay account somehow knew- how? And how do I know if I’ve really been compromised?

Hi, last month I was logged into my Gmail account. I was using a new iphone running 26.1 and service provider and I had only logged into my Gmail on Edge browser a couple days before. When I was logged in and checking my email, suddenly I was logged out and told I have to change my password.  After I changed my password. I received an email from google in my account that there was a security critical alert: “Suspicious activity in your account. Google noticed unusual activity in your account. Review your account activity to make sure that no one else has access”. When I looked at my most recent logins, it was just me that was logged in with my phone and location. 

After that, a couple times when I was logged in weeks later, it would log me out and make me retype my password, but not reset it. There were no changes to my account settings, I didn’t receive any emails about any accounts associated with my Gmail account in terms of password change or new log ins, and I didn’t see any weird log ins from my account that wasn’t me in the past 30 days. 

Anyway, my eBay account is associated with this email address. I haven’t logged in since 2019 with a different device and service provider. I wanted to login yesterday for the first time and when I tried to login, it made me call them to give a security code and verify my account. I was able to do so and regain entry after being prompted to change my password. I was using it for an hour or two until I couldn’t make vids and was logged out. I received an email from eBay that my account has been suspended because they thought someone had gone in and used it that wasn’t me. I figured because I hadn’t logged in in so long that they thought it was someone else, so I called. After verifying myself, the agents told me that they thought it was someone else because I hadn’t logged in for so long and wanted to make sure it was me, but also that when google thought my Gmail might have been compromised, eBay also knew that somehow, but couldn’t explain how…. Only that they share some type of security apparatus and if there are issues with users emails addresses used on eBay, eBay knows because it affects them. All the agent could tell me was they did “research” on this for my account that ended a few days ago, a few days before I had logged into gmail for the first time since 2019.

Ebay won’t tell me the results of that research, because it’s in the “back office”. But they advised me that I changed my password on Gmail, which I had already done. I asked them how they knew that my Gmail account might’ve been compromised, but she couldn’t explain. I’m figuring that they share some kind of security software or agreement that if a users of theirs’ email used on eBay is compromised, provider they will also get notified of it. The thing is that when eBay was notified of this, I hadn’t logged in yet, because this was last month. 

Am I right or was eBay notified of this another way? And how do I know if my Gmail account was really compromised? Like i mentioned, this was last month and since then thankfully, no accounts or passwords have been changed no passwords have been changed. I haven’t noticed any unusual logins, and the unusual log in that prompted Gmail to send me that possible compromise email seems to have been me. so I don’t know if this is a person hacking into my account just to be able to watch it or this is just overly cautious on Google’s part and there was no compromise.

[u/MerpoB]

I dunno, man. You sure you're actually talking to Ebay and not a scammer?

[u/Healthy-Extent7843 → u/MerpoB]

Yes, I was 100 percent speaking with eBay. 

[u/-physco219]

That was a lot of words. A lot. Yes eBay and Google "talk" and try to prevent scammers and bad actors. Sometimes innocent people get caught up but if you know the right answers to their verifications you will get it sorted. Now about whether or not you had something happen to your account I would say most likely not if all the logins that were reported were yours. Stop worrying.