What’s a denial-of-service attack?

A denial-of-service (DoS) attack occurs when genuine users are unable to access information systems, devices, or other network resources due to the activities of a malicious cyber threat actor. Services affected may involve email, websites, online accounts (e.g., banking), or other services that rely on the affected computer or network. A denial-of-service is accomplished by inundating the targeted host or network with traffic until the target cannot respond or basically crashes, stopping access for legitimate users. DoS attacks can cost an organization both time and money while their resources and services are unreachable.