Whenever you log into your Steam account from another device that is not recognized, the software will require you to provide a special access code to proceed and verify the account.

Steam is an online gaming application that allows you to access video games in the Cloud. By default, each time that you want to access your Steam account from an unrecognized device, you must ...

EnergyWeaponUser, a known cybercriminal and leaker, is selling a new database which, they claim, holds more than 89 million Steam user records, phone numbers, and one-time access codes.