I just completed my backup phrase security setup with blockchain after I was prompted to click finish. As soon as I click it the account confirmed a transaction I did not do transferring almost all my bitcoin to an unknown address. Could someone explain to me what happened and if I can get back my fund?
I would expect that Blockchain sets up your backup and security when you create an account. If you got prompted to put in your wallet information at a later time, that would have almost certainly been a phishing attack. I suspect that you were on a website that was not blockchain.info and the mock security setup provided the information to empty your account to your attacker.