Potential Password Spraying of Microsoft 365 User Accounts
editPotential Password Spraying of Microsoft 365 User Accounts
editIdentifies a high number (25) of failed Microsoft 365 user authentication attempts from a single IP address within 30 minutes, which could be indicative of a password spraying attack. An adversary may attempt a password spraying attack to obtain unauthorized access to user accounts.
Rule type: threshold
Rule indices:
- filebeat-*
- logs-o365*
Severity: high
Risk score: 73
Runs every: 5 minutes
Searches indices from: now-30m (Date Math format, see also Additional look-back time)
Maximum alerts per execution: 100
Tags:
- Elastic
- Cloud
- Microsoft 365
- Continuous Monitoring
- SecOps
- Identity and Access
Version: 1
Added (Elastic Stack release): 7.11.0
Rule authors: Elastic
Rule license: Elastic License
Potential false positives
editAutomated processes that attempt to authenticate using expired credentials and unbounded retries may lead to false positives.
Investigation guide
editThe Microsoft 365 Fleet integration or Filebeat module must be enabled to use this rule.
Rule query
editevent.dataset:o365.audit and event.provider:AzureActiveDirectory and event.category:authentication and event.action:UserLoginFailed and event.outcome:failure
Threat mapping
editFramework: 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/