You should change your Yahoo email password.
Tech Talk #65 – Nov. 25, 2017 You should change your Yahoo email password. They call it largest known theft of user data in history. In an August 2013 data breach at Yahoo, all 3 billion account holders at Yahoo had their info stolen. What info, you ask? Oh, just user account information, including names, email addresses, telephone numbers, dates of birth, hashed passwords (using MD5), and, in some cases, "encrypted or unencrypted security