Find sigma rule 
Attack: Email Collection: Remote Email Collection
Adversaries may target an Exchange server, Office 365, or Google Workspace to collect sensitive information. Adversaries may leverage a user’s credentials and interact directly with the Exchange server to acquire information from within a network. Adversaries may also access externally facing Exchange services, Office 365, or Google Workspace to access email using credentials or access tokens. Tools such as MailSniper can be used to automate searches for specific keywords.
MITRE
Tactic
- collection
technique
- T1114.002
Test : Office365 - Remote Mail Collected
OS
- office-365
Description:
Create and register an entra application that downloads emails from a tenant’s Office 365 mailboxes using the Microsoft Graph API app-only access. This can be used by an adversary to collect an organization’s sensitive information.
Executor
powershell