Somebody created projects on Google Cloud in my account without my knowledge

When I access Google Cloud, I see some projects that I haven't created. It seems I can't delete them too, I lack permissions to manage them. I am not using anything from Google Cloud at the moment and want to get rid of all of them. Also one of these projects are listed on Firebase as well, where I also don't have permission to delete it.

I haven't seen any evidence that my Google account has been compromised, Gmail activity seems to be fine, haven't seen any suspicious access in Gmail, and I have 2FA activated. The security checkup page in myaccount.google.com shows all green as well... So I'm really confused on how someone could access my Google Cloud account and create projects that I don't have admin access in.

So the question is, how can I delete these projects from my Google Cloud and Firebase accounts?

TL;DR: these projects probably weren't created by my user, even though they show on Google Cloud and Firebase console, so most likely my Google account wasn't compromised. It seems it's possible to include users in projects without them having any say in it, and then these projects show in the console and there's no easy way to have them removed. Apparently they showed up because of my account's Google Groups subscriptions. I removed myself from all groups and the projects disappeared. I wasn't the only one with problems removing myself from projects, as we can see on this issue and this issue, opened in Google's issue tracker.

Additional information: I just got an answer from Firebase support (I had opened an issue with them regarding this problem). They explained that project owners are allowed to add Google Groups to their projects, and anyone who is in that group will have that project show up on console. The easiest way to get rid of that project is to leave the group.

When I access Google Cloud, I see some projects that I haven't created.

Seeing projects does not mean your account created them. Someone may have given you access to those projects. Find out what rights you have to those projects with this command:

gcloud projects get-iam-policy <YOUR GCLOUD PROJECT ID> \
--flatten="bindings[].members" \
--format='table(bindings.role)' \
--filter="bindings.members:<YOUR EMAIL ADDRESS>"

To find out who has what roles in each project (look for the owner role):

gcloud projects get-iam-policy <YOUR GCLOUD PROJECT ID>

One key item is if these projects are part of an organization. If so, what role s do you have at the organization level. With the correct roles, you can grant any rights you want to each project.

The next step is to find out if your billing account is assigned to any of these projects:

gcloud beta billing accounts list

Make note of the ACCOUNT_ID for the next command:

gcloud alpha billing projects list ACCOUNT_ID

If your billing account is being used fraudulently, remove the payment instrument (credit/debit card) from the billing account, remove their access to your billing account and then contact Google Cloud Billing Support.