Okta Authentication Failed During MFA Challenge

This analytic identifies failed authentication attempts during the Multi-Factor Authentication (MFA) challenge in an Okta tenant. It specifically looks for events where the authentication signature is `user.authentication.auth_via_mfa` and the action is `failure`. This activity is significant as it may indicate an adversary attempting to authenticate with compromised credentials on an account with MFA enabled, potentially suggesting an ongoing attempt to bypass MFA protections and gain unauthorized access.