Session cookie hijacking

Why MFA Isn't "Game Over"

Think of MFA as a sturdy front-door lock; it’s essential, but it isn’t the only way into the house. After you log in, your browser stay authenticated via a session token (usually a cookie). Think of it like a festival wristband: once you’ve passed security, the wristband proves you belong there. If a criminal steals that wristband, they can stroll right past your MFA.

This is session cookie hijacking. The attacker isn't "cracking" your MFA; they are simply replaying a session you’ve already authorised. While MFA is a vital upgrade, it isn't a silver bullet. Attackers now focus on circumventing the login process rather than beating it head-on. As Cloudflare and Microsoft note, modern incidents often involve "Adversary-in-the-Middle" (AiTM) attacks, where a proxy site intercepts your password and session cookie simultaneously. This isn't a flaw in MFA itself—it’s an exploit of what happens after the login.