IMPORTANT: No additional bug fixes or documentation updates will be released for this version. For the latest information, see the current release documentation.
« Multiple Okta User Auth Events with Same Device Token Hash Behind a Proxy Multiple Okta User Authentication Events with Client Address »
Elastic Docs ›Elastic Security Solution [8.15] ›Downloadable rule update v8.15.6

Multiple Device Token Hashes for Single Okta Session

edit

Multiple Device Token Hashes for Single Okta Session

edit

This rule detects when a specific Okta actor has multiple device token hashes for a single Okta session. This may indicate an authenticated session has been hijacked or is being used by multiple devices. Adversaries may hijack a session to gain unauthorized access to Okta admin console, applications, tenants, or other resources.

Rule type: esql

Rule indices: None

Severity: medium

Risk score: 47

Runs every: 5m

Searches indices from: now-9m (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: Credential Access
  • Domain: SaaS

Version: 103

Rule authors:

  • Elastic

Rule license: Elastic License v2

Investigation guide

edit

Triage and analysis

Investigating Multiple Device Token Hashes for Single Okta Session

This rule detects when a specific Okta actor has multiple device token hashes for a single Okta session. This may indicate an authenticated session has been hijacked or is being used by multiple devices. Adversaries may hijack a session to gain unauthorized access to Okta admin console, applications, tenants, or other resources.

Possible investigation steps:

  • Since this is an ES|QL rule, the okta.actor.alternate_id and okta.authentication_context.external_session_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.
  • Authentication events have been filtered out to focus on Okta activity via established sessions.
  • 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.
  • Aggregate by okta.actor.alternate_id and event.action to determine the type of actions that are being performed by the actor(s) involved in this action.
  • If various activity is reported that seems to indicate actions from separate users, consider deactivating the user’s account temporarily.

False positive analysis:

  • It is very rare that a legitimate user would have multiple device token hashes for a single Okta session as DT hashes do not change after an authenticated session is established.

Response and remediation:

  • Consider stopping all sessions for the user(s) involved in this action.
  • If this does not appear to be a false positive, consider resetting passwords for the users involved 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.
  • 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

edit

Setup

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

Rule query

edit
FROM logs-okta*
| WHERE
    event.dataset == "okta.system"
    // ignore authentication events where session and device token hash change often
    AND NOT event.action IN (
        "policy.evaluate_sign_on",
        "user.session.start",
        "user.authentication.sso"
    )
    // ignore Okta system events and only allow registered users
    AND (
        okta.actor.alternate_id != "system@okta.com"
        AND okta.actor.alternate_id RLIKE "[^@\\s]+\\@[^@\\s]+"
    )
    AND okta.authentication_context.external_session_id != "unknown"
| STATS
    dt_hash_counts = COUNT_DISTINCT(okta.debug_context.debug_data.dt_hash) BY
        okta.actor.alternate_id,
        okta.authentication_context.external_session_id
| WHERE
    dt_hash_counts >= 2
| SORT
    dt_hash_counts DESC

Framework: MITRE ATT&CKTM

« Multiple Okta User Auth Events with Same Device Token Hash Behind a Proxy Multiple Okta User Authentication Events with Client Address »