Remote Email Collection
Where this stands
One published detection covers this technique. Every one is unverified — no rule on Siemphony has been executed against real telemetry.
What the technique is
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.
Read it on attack.mitre.orgWhat MITRE says you would watch
- AN0131
Detects adversaries accessing remote mail systems (e.g., Exchange Online, O365) using stolen credentials or OAuth tokens, followed by scripted access to mailbox contents via PowerShell, AADInternals, or unattended API queries. Detection focuses on abnormal logon sessions, user agents, IP locations, and scripted or tool-based email data access.
- AN0132
Monitors programmatic access to user mailboxes in cloud-based email systems (e.g., O365, Exchange Online) using APIs or tokens. Focuses on OAuth misuse, suspicious MailItemsAccessed patterns, scripted keyword searches, and connections from untrusted agents or locations.
Technique names and descriptions © MITRE ATT&CK®, CC BY 4.0. Not endorsed by MITRE.