I have used blockchain.info as a place to store one of my wallets for many years now.
But blockchain.com isn't a place to store your wallets for many years! You have to understand that you're trusting your laptop and every program it has installed, your email service, your phone (if it has access to your email account) and blockchain.com itself.Any ideas on how this happened?
There are millions of ideas on how did this happen, but I'd say the most probable: The phone had something malicious installed. I'm sorry for your four thousands of dollars damage. I hope you now know that you should never store any bitcoin online. Use non-custodian wallets instead.I don't have Russian or Chinese ringtone apps on my phone.
What does that have to do with your security? 