The 'Okta AiTM Phishing Attempt Blocked by FastPass' rule is designed to protect users from credential theft attacks that utilize Account takeover methods via phishing. This rule triggers when Okta's FastPass service detects a user targeted by attackers employing real-time (AiTM) proxies to gain unauthorized access during authentication attempts. In cases where suspicious activity is recognized, the system logs events reflecting users who failed to authenticate while attempting to bypass security measures such as MFA. The rule utilizes Okta System Logs as its primary source of data, and has a high severity rating due to the potential risk of malicious account access. When triggered, the rule instructs the system to deny access and block the intrusion attempt automatically, ensuring an additional layer of protection against phishing attacks. The implementation of FIDO2 WebAuthn further strengthens the defense against phishing by requiring robust, phishing-resistant authentication methods. The overall recommendation is to continuously monitor and enforce best practices for secure authentication to mitigate identity-related threats.