Cybersecurity glossary
What is account takeover?
Also known as: ATO
Definition
Account takeover is when a criminal gains control of someone else’s online account, usually with a stolen or reused password, a phished one-time code or a hijacked session.
Why it matters
Once inside, attackers often change the recovery email or phone number, add forwarding rules, and use the account to scam the owner’s contacts or reset passwords on other services.
Unique passwords, multi-factor authentication (ideally passkeys or security keys) and alerts for new sign-ins are the main defenses.
Common questions about account takeover
See also
Sources
Related Guides
GuideIncident Response
The Binance Hack Timeline: How a 93-Cent Transaction Drained $6.3 Billion
A minute-by-minute account of the October 2026 Binance hack: the EIP-7702 sweep, the freeze race, the "one laptop" explanation, the North Korea attribution and where the money is now.
Read more GuidePersonal Security
7 Signs Your Account Has Been Hacked (and How to Fix It)
Spot the warning signs your account has been hacked, learn immediate containment steps, and restore your digital security with practical defensive advice.
Read more GuideAI Security
AI Agent Security: Implementing Least Privilege for Tools
Learn how to enforce least privilege for AI agent security. Control tool calling, scope data access, and prevent unauthorized actions in production.
Read more GuideGRC
How to Run a User Access Review Process: A Step-by-Step Guide
Learn how to execute an effective user access review process. Audit permissions, eliminate privilege creep, and satisfy core compliance controls.
Read more