What is multi-factor authentication (MFA)?

MFA requires two or more independent forms of verification — such as a password plus a code or hardware key — before granting access. It dramatically reduces the risk of account compromise from stolen passwords, a common ransomware entry point.

Phishing-resistant MFA such as FIDO2 is strongest. MFA reduces the odds of compromise, but it does not guarantee recovery, which is why clean, verifiable backups remain essential.