Okta Multiple Users Failing To Authenticate From Ip

name: Okta Multiple Users Failing To Authenticate From Ip
id: de365ffa-42f5-46b5-b43f-fa72290b8218
version: 11
creation_date: '2024-04-17'
modification_date: '2026-05-13'
author: Michael Haag, Mauricio Velazco, Splunk
status: production
type: Anomaly
description: The following analytic identifies instances where more than 10 unique user accounts have failed to authenticate from a single IP address within a 5-minute window in an Okta tenant. This detection uses OktaIm2 logs ingested via the Splunk Add-on for Okta Identity Cloud. Such activity is significant as it may indicate brute-force attacks or password spraying attempts. If confirmed malicious, this behavior suggests an external entity is attempting to compromise multiple user accounts, potentially leading to unauthorized access to organizational resources and data breaches.
data_source:
    - Okta
search: |-
    | tstats `security_content_summariesonly` count max(_time) as lastTime, min(_time) as firstTime dc(Authentication.user) as unique_accounts values(Authentication.signature) as signature values(Authentication.user) as user values(Authentication.app) as app values(Authentication.authentication_method) as authentication_method values(Authentication.dest) as dest FROM datamodel=Authentication
      WHERE Authentication.action="failure"
        AND
        Authentication.signature=user.session.start
      BY _time span=5m Authentication.src
         sourcetype
    | where unique_accounts > 9
    | `drop_dm_object_name("Authentication")`
    | `security_content_ctime(firstTime)`
    | `security_content_ctime(lastTime)`
    | `okta_multiple_users_failing_to_authenticate_from_ip_filter`
how_to_implement: The analytic leverages Okta OktaIm2 logs to be ingested using the Splunk Add-on for Okta Identity Cloud (https://splunkbase.splunk.com/app/6553).
known_false_positives: A source Ip failing to authenticate with multiple users in a short period of time is not common legitimate behavior.
references:
    - https://attack.mitre.org/techniques/T1110/003/
    - https://splunkbase.splunk.com/app/6553
intermediate_findings:
    entities:
        - field: user
          type: user
          score: 20
          message: Multiple users failing to authenticate from a single source IP Address - [$src$]. Investigate further to determine if this was authorized.
threat_objects:
    - field: src
      type: ip_address
analytic_story:
    - Okta Account Takeover
asset_type: Okta Tenant
mitre_attack_id:
    - T1110.003
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: application
security_domain: identity