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Okta User Sessions Started from Different Geolocations

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Okta User Sessions Started from Different Geolocations

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Detects when a specific Okta actor has multiple sessions started from different geolocations. Adversaries may attempt to launch an attack by using a list of known usernames and passwords to gain unauthorized access to user accounts from different locations.

Rule type: esql

Rule indices: None

Severity: medium

Risk score: 47

Runs every: 15m

Searches indices from: now-30m (Date Math format, see also Additional look-back time)

Maximum alerts per execution: 100

References:

Tags:

  • Use Case: Identity and Access Audit
  • Data Source: Okta
  • Tactic: Initial Access

Version: 303

Rule authors:

  • Elastic

Rule license: Elastic License v2

Investigation guide

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Triage and analysis

Investigating Okta User Sessions Started from Different Geolocations

This rule detects when a specific Okta actor has multiple sessions started from different geolocations. Adversaries may attempt to launch an attack by using a list of known usernames and passwords to gain unauthorized access to user accounts from different locations.

Possible investigation steps:

  • Since this is an ES|QL rule, the okta.actor.alternate_id and okta.client.id values can be used to pivot into the raw authentication events related to this alert.
  • Identify the users 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 device client used for these actions by analyzing okta.client.ip, okta.client.user_agent.raw_user_agent, okta.client.zone, okta.client.device, and okta.client.id fields.
  • With Okta end users identified, review the okta.debug_context.debug_data.dt_hash field.
  • Historical analysis should indicate if this device token hash is commonly associated with the user.
  • Review the okta.event_type field to determine the type of authentication event that occurred.
  • If the event type is user.authentication.sso, the user may have legitimately started a session via a proxy for security or privacy reasons.
  • If the event type is user.authentication.password, the user may be using a proxy to access multiple accounts for password spraying.
  • If the event type is user.session.start, the source may have attempted to establish a session via the Okta authentication API.
  • Review the past activities of the actor(s) involved in this action by checking their previous actions.
  • 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.
  • This may help determine the authentication and authorization actions that occurred between the user, Okta and application.

False positive analysis:

  • It is very rare that a legitimate user would have multiple sessions started from different geo-located countries in a short time frame.

Response and remediation:

  • If the user is legitimate and the authentication behavior is not suspicious based on device analysis, no action is required.
  • If the user is legitimate but the authentication behavior is suspicious, consider resetting passwords for the users involves and enabling multi-factor authentication (MFA).
  • If MFA is already enabled, consider resetting MFA for the users.
  • If any of the users are not legitimate, consider deactivating the user’s account.
  • Conduct a review of Okta policies and ensure they are in accordance with security best practices.
  • Check with internal IT teams to determine if the accounts involved recently had MFA reset at the request of the user.
  • If so, confirm with the user this was a legitimate request.
  • If so and this was not a legitimate request, consider deactivating the user’s account temporarily.
  • Reset passwords and reset MFA for the user.
  • If this is a false positive, consider adding the okta.debug_context.debug_data.dt_hash field to the exceptions list in the rule.
  • This will prevent future occurrences of this event for this device from triggering the rule.
  • Alternatively adding okta.client.ip or a CIDR range to the exceptions list can prevent future occurrences of this event from triggering the rule.
  • This should be done with caution as it may prevent legitimate alerts from being generated.

Setup

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The Okta Fleet integration, Filebeat module, or similarly structured data is required to be compatible with this rule.

Rule query

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FROM logs-okta*
| WHERE
    event.dataset == "okta.system"
    AND (event.action RLIKE "user\\.authentication(.*)" OR event.action == "user.session.start")
    AND okta.security_context.is_proxy != true and okta.actor.id != "unknown"
    AND event.outcome == "success"
| KEEP event.action, okta.security_context.is_proxy, okta.actor.id, event.outcome, client.geo.country_name, okta.actor.alternate_id
| STATS
    geo_auth_counts = COUNT_DISTINCT(client.geo.country_name)
    BY okta.actor.id, okta.actor.alternate_id
| WHERE
    geo_auth_counts >= 2

Framework: MITRE ATT&CKTM

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