IMPORTANT: No additional bug fixes or documentation updates
will be released for this version. For the latest information, see the
current release documentation.
Attempts to Brute Force a Microsoft 365 User Account
editAttempts to Brute Force a Microsoft 365 User Account
editIdentifies attempts to brute force a Microsoft 365 user account. An adversary may attempt a brute force attack to obtain unauthorized access to user accounts.
Rule type: threshold
Rule indices:
- filebeat-*
- logs-o365*
Severity: high
Risk score: 73
Runs every: 5m
Searches indices from: now-30m (Date Math format, see also Additional look-back time)
Maximum alerts per execution: 100
References:
Tags:
- Domain: Cloud
- Data Source: Microsoft 365
- Use Case: Identity and Access Audit
- Tactic: Credential Access
Version: 208
Rule authors:
- Elastic
- Willem D’Haese
- Austin Songer
Rule license: Elastic License v2
Investigation guide
editSetup
editThe Office 365 Logs Fleet integration, Filebeat module, or similarly structured data is required to be compatible with this rule.
Rule query
editevent.dataset:o365.audit and event.provider:(AzureActiveDirectory or Exchange) and
event.category:authentication and event.action:(UserLoginFailed or PasswordLogonInitialAuthUsingPassword) and
not o365.audit.LogonError:(UserAccountNotFound or EntitlementGrantsNotFound or UserStrongAuthEnrollmentRequired or
UserStrongAuthClientAuthNRequired or InvalidReplyTo or SsoArtifactExpiredDueToConditionalAccess or
PasswordResetRegistrationRequiredInterrupt or SsoUserAccountNotFoundInResourceTenant or
UserStrongAuthExpired)
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/