Some of the most common indicators that you may have been include the following. Your friends tell you that they have received odd emails or messages from you, messages you know you did not send. Your password no longer works for one of your accounts, even though you know you never changed the password. Your anti-virus informs you that one of your files or computer is infected. You receive a pop-up message informing you that the files on your computer have been encrypted and you must pay a ransom to recover them.