Account takeover fraud—in which bad actors use stolen credentials to commandeer real credit card, shopping or even government benefit accounts—is one of the most common forms of identity theft. In fact, a 2020 study by Aite Group found that 38% of consumers surveyed had recently experienced account takeover fraud in the prior two years. It's pervasive and difficult to detect, and it can cost you money, wreak havoc with your finances and consume your valuable time while you try to undo the damage and secure your accounts. Here's what you need to know about account takeover fraud and how to protect yourself.