It was stolen because the number of a Trojan horse was stolen from your computer. Unless you get rid of the virus in your computer and change your password, even if you change your password now, the other party will still know your password, because pilfer date trojan of your own computer is still there. As soon as you log in to QQ system, you will automatically send your password to his mailbox! ! So it should be dealt with as soon as possible. I used 360 guards to solve it.