Some of the most common indicators that you may have been hacked 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.