Okta Brute Force or Password Spraying Attack

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Identifies a high number of failed Okta user authentication attempts from a single IP address, which could be indicative of a brute force or password spraying attack. An adversary may attempt a brute force or password spraying attack to obtain unauthorized access to user accounts.

Rule type: threshold

Rule indices:

  • filebeat-*
  • logs-okta*

Severity: medium

Risk score: 47

Runs every: 5m

Searches indices from: None (Date Math format, see also Additional look-back time)

Maximum alerts per execution: 100

References:

Tags:

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

Version: 211

Rule authors:

  • Elastic

Rule license: Elastic License v2

Investigation guide

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Triage and analysis

Investigating Okta Brute Force or Password Spraying Attack

This rule alerts when a high number of failed Okta user authentication attempts occur from a single IP address. This could be indicative of a brute force or password spraying attack, where an adversary may attempt to gain unauthorized access to user accounts by guessing the passwords.

Possible investigation steps:

  • Review the source.ip field to identify the IP address from which the high volume of failed login attempts originated.
  • Look into the event.outcome field to verify that these are indeed failed authentication attempts.
  • Determine the user.name or user.email related to these failed login attempts. If the attempts are spread across multiple accounts, it might indicate a password spraying attack.
  • Check the timeline of the events. Are the failed attempts spread out evenly, or are there burst periods, which might indicate an automated tool?
  • Determine the geographical location of the source IP. Is this location consistent with the user’s typical login location?
  • Analyze any previous successful logins from this IP. Was this IP previously associated with successful logins?

False positive analysis:

  • A single user or automated process that attempts to authenticate using expired or wrong credentials multiple times may trigger a false positive.
  • Analyze the behavior of the source IP. If the IP is associated with legitimate users or services, it may be a false positive.

Response and remediation:

  • If you identify unauthorized access attempts, consider blocking the source IP at the firewall level.
  • Notify the users who are targeted by the attack. Ask them to change their passwords and ensure they use unique, complex passwords.
  • Enhance monitoring on the affected user accounts for any suspicious activity.
  • If the attack is persistent, consider implementing CAPTCHA or account lockouts after a certain number of failed login attempts.
  • If the attack is persistent, consider implementing multi-factor authentication (MFA) for the affected user accounts.
  • Review and update your security policies based on the findings from the incident.

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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event.dataset:okta.system and event.category:authentication and event.outcome:failure

Framework: MITRE ATT&CKTM