My coinbase got hacked today. I got a message on my phone saying that my password had changed. I attempted to follow instructions to stop it, but by the time I had, it was too late and the theif emptied out my hot wallet. The only saving grace was that coinbase has vaults which give 48 hour delay. I wish that I would have transferred more coins to the vault as they were protected. Coinbase has some serious vulnerabilities, but whoever the thief was was able to login from my IP and was able to login to my email despite the fact that I had just changed my password. Be careful out there. Cold wallet your coins.
I just know about the coinbase has 2fa verification and why you are no using it. The possible thing about you were getting phishing. If the hacker be able to login into your email and that will be the end of the story.
Or another speculation about your computer got infected by ransom ware. Remember to not to publicly your email address that has used to store all of your data.