What Is Account Takeover (ATO)?

Account takeover is when an attacker gains unauthorized control of a legitimate user's account, most commonly through credential stuffing, phishing, or reusing credentials leaked in an unrelated breach, then uses that access for fraud, data theft, or as a foothold for further attack.

It's difficult to catch through login monitoring alone, since a successful takeover uses a valid username and password — the signal that distinguishes it from a real login is behavioral and contextual, not credential-based.

MaskFlare Radar detects the high-velocity, automated login patterns that precede account takeover, stopping credential-stuffing attempts before an attacker finds a working pair, and flags anomalous post-login behavior that suggests a session isn't the real account owner.