Microsoft 365 New Inbox Rule Creatededit

Identifies when a new Inbox rule is created in Microsoft 365. Inbox rules process messages in the Inbox based on conditions and take actions, such as moving a message to a specified folder or deleting a message. Adequate permissions are required on the mailbox to create an Inbox rule.

Rule type: query

Rule indices:

  • filebeat-*
  • logs-o365*

Severity: low

Risk score: 21

Runs every: 5 minutes

Searches indices from: now-30m (Date Math format, see also Additional look-back time)

Maximum alerts per execution: 100

References:

Tags:

  • Elastic
  • Cloud
  • Microsoft 365
  • Continuous Monitoring
  • SecOps
  • Configuration Audit

Version: 1

Added (Elastic Stack release): 7.13.0

Rule authors: Elastic, Gary Blackwell, Austin Songer

Rule license: Elastic License v2

Potential false positivesedit

An inbox rule may be created by a system or network administrator. Verify that the configuration change was expected. Exceptions can be added to this rule to filter expected behavior.

Investigation guideedit

Config

The Microsoft 365 Fleet integration, Filebeat module, or similarly structured data is required to be compatible with this rule.

Rule queryedit

event.dataset:o365.audit and event.provider:Exchange and
event.category:web and event.action:"New-InboxRule" and
event.outcome:success

Threat mappingedit

Framework: MITRE ATT&CKTM