T1114.003: Email Forwarding Rule
| View on MITRE ATT&CK | T1114.003 |
|---|---|
| Tactic(s) | Collection |
Data from MITRE ATT&CK®:
Adversaries may setup email forwarding rules to collect sensitive information. Adversaries may abuse email forwarding rules to monitor the activities of a victim, steal information, and further gain intelligence on the victim or the victim’s organization to use as part of further exploits or operations.(Citation: US-CERT TA18-068A 2018) Furthermore, email forwarding rules can allow adversaries to maintain persistent access to victim's emails even after compromised credentials are reset by administrators.(Citation: Pfammatter - Hidden Inbox Rules) Most email clients allow users to create inbox rules for various email functions, including forwarding to a different recipient. These rules may be created through a local email application, a web interface, or by command-line interface. Messages can be forwarded to internal or external recipients, and there are no restrictions limiting the extent of this rule. Administrators may also create forwarding rules for user accounts with the same considerations and outcomes.(Citation: Microsoft Tim McMichael Exchange Mail Forwarding 2)(Citation: Mac Forwarding Rules)
Any user or administrator within the organization (or adversary with valid credentials) can create rules to automatically forward all received messages to another recipient, forward emails to different locations based on the sender, and more. Adversaries may also hide the rule by making use of the Microsoft Messaging API (MAPI) to modify the rule properties, making it hidden and not visible from Outlook, OWA or most Exchange Administration tools.(Citation: Pfammatter - Hidden Inbox Rules)
In some environments, administrators may be able to enable email forwarding rules that operate organization-wide rather than on individual inboxes. For example, Microsoft Exchange supports transport rules that evaluate all mail an organization receives against user-specified conditions, then performs a user-specified action on mail that adheres to those conditions.(Citation: Microsoft Mail Flow Rules 2023) Adversaries that abuse such features may be able to enable forwarding on all or specific mail an organization receives.
© 2024 The MITRE Corporation. This work is reproduced and distributed with the permission of The MITRE Corporation.
Cyber Threat Graph Context
Explore how this ATT&CK Technique relates to the wider threat graph
Mitigations for this technique
MITRE ATT&CK Mitigations
Audit
Perform audits or scans of systems, permissions, insecure software, insecure configurations, etc. to identify potential weaknesses.Disable or Remove Feature or Program
Remove or deny access to unnecessary and potentially vulnerable software to prevent abuse by adversaries.Encrypt Sensitive Information
Protect sensitive information with strong encryption.How to detect this technique
MITRE ATT&CK Data Components
Command Execution (Command)
The execution of a line of text, potentially with arguments, created from program code (e.g. a cmdlet executed via powershell.exe, interactive commands like >dir, shell executions, etc. )Application Log Content (Application Log)
Logging, messaging, and other artifacts provided by third-party services (ex: metrics, errors, and/or alerts from mail/web applications)Control Validation Tests for this Technique
Use Atomic Red Team tests to test your defenses against this technique.
SP800-53 Controls
See which controls can help protect against this MITRE ATT&CK technique. This is based on mappings to associated SP800-53 controls produced by the MITRE Engenuity Center for Threat-Informed Defense.