When someone logs into your site, how do you tell the difference between legitimate use and credential stuffing? Not knowing if a login is coming from a real user or a software program imitating one makes your business vulnerable to fraud.

With the proliferation of online applications, most users don’t practice good Internet hygiene — often repurposing the same login credentials across multiple accounts. That makes every online business with a login page a potential target for credential stuffing, whether you’ve had a data breach or not.

The higher the transaction value, the more that is at risk. A fraudster can purchase goods from an online store, take out bank loans from a financial institution, or steal medical information from a healthcare site. Credential stuffing can hurt your business, customers, and brand — and it is a problem so stealthy that you need specialized tools to detect and defend against it.

Understanding credential stuffing threats, their increasing sophistication, and the best approaches for stopping them can help you safeguard your business.