New Okta Authentication Behavior Detected

## Triage and analysis

### Investigating New Okta Authentication Behavior Detected

This rule detects events where Okta behavior detection has identified a new authentication behavior such as a new device or location.

#### Possible investigation steps:
- Identify the user involved in this action by examining the `okta.actor.id`, `okta.actor.type`, `okta.actor.alternate_id`, and `okta.actor.display_name` fields.
- Determine the authentication anomaly by examining the `okta.debug_context.debug_data.risk_behaviors` and `okta.debug_context.debug_data.flattened` fields.
- Determine the client used by the actor. Review the `okta.client.ip`, `okta.client.user_agent.raw_user_agent`, `okta.client.zone`, `okta.client.device`, and `okta.client.id` fields.
- If the client is a device, check the `okta.device.id`, `okta.device.name`, `okta.device.os_platform`, `okta.device.os_version`, and `okta.device.managed` fields.
- Review the past activities of the actor involved in this action by checking their previous actions.
- Examine the `okta.request.ip_chain` field to potentially determine if the actor used a proxy or VPN to perform this action.
- Evaluate the actions that happened just before and after this event in the `okta.event_type` field to help understand the full context of the activity.

### False positive analysis:
- A user may be using a new device or location to sign in.
- The Okta behavior detection may be incorrectly identifying a new authentication behavior and need adjusted.

### Response and remediation:
- If the user is legitimate and the authentication behavior is not suspicious, no action is required.
- If the user is legitimate but the authentication behavior is suspicious, consider resetting the user's password and enabling multi-factor authentication (MFA).
    - If MFA is already enabled, consider resetting MFA for the user.
- If the user is not legitimate, consider deactivating the user's account.
- If this is a false positive, consider adjusting the Okta behavior detection settings.
- Block the IP address or device used in the attempts if they appear suspicious, using the data from the `okta.client.ip` and `okta.device.id` fields.
- Conduct a review of Okta policies and ensure they are in accordance with security best practices.