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Multiple Okta User Auth Events with Same Device Token Hash Behind a Proxy
editMultiple Okta User Auth Events with Same Device Token Hash Behind a Proxy
editDetects when Okta user authentication events are reported for multiple users with the same device token hash behind a proxy.
Rule type: threshold
Rule indices:
- filebeat-*
- logs-okta*
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
Version: 2
Rule authors:
- Elastic
Rule license: Elastic License v2
Investigation guide
edit## Triage and analysis ### Investigating Multiple Okta User Auth Events with Same Device Token Hash Behind a Proxy This rule detects when Okta user authentication events are reported for multiple users with the same device token hash behind a proxy. This may indicate that a shared device between users, or that a user is using a proxy to access multiple accounts for password spraying. #### Possible investigation steps: - 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. - Since the device is behind a proxy, the `okta.client.ip` field will not be useful for determining the actual device IP address. - Review the `okta.request.ip_chain` field for more information about the geographic location of the proxy. - 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. - Examine the `okta.outcome.result` field to determine if the authentication was successful. - 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: - A user may have legitimately started a session via a proxy for security or privacy reasons. - Users may share an endpoint related to work or personal use in which separate Okta accounts are used. - Architecturally, this shared endpoint may leverage a proxy for security or privacy reasons. - Shared systems such as Kiosks and conference room computers may be used by multiple users. - Shared working spaces may have a single endpoint that is used by multiple users. ### Response and remediation: - Review the profile of the users involved in this action to determine if proxy usage may be expected. - 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.
Rule query
editevent.dataset:okta.system and not okta.actor.id:okta* and okta.debug_context.debug_data.dt_hash:* and okta.event_type:user.authentication* and okta.security_context.is_proxy:true
Framework: MITRE ATT&CKTM
-
Tactic:
- Name: Credential Access
- ID: TA0006
- Reference URL: https://attack.mitre.org/tactics/TA0006/
-
Technique:
- Name: Brute Force
- ID: T1110
- Reference URL: https://attack.mitre.org/techniques/T1110/
-
Sub-technique:
- Name: Password Spraying
- ID: T1110.003
- Reference URL: https://attack.mitre.org/techniques/T1110/003/
-
Technique:
- Name: Brute Force
- ID: T1110
- Reference URL: https://attack.mitre.org/techniques/T1110/
-
Sub-technique:
- Name: Credential Stuffing
- ID: T1110.004
- Reference URL: https://attack.mitre.org/techniques/T1110/004/