MITRE ATT&CK sub-technique
T1564.008 — Email Hiding Rules
Last fetched
T1564.008 (Email Hiding Rules) is a MITRE ATT&CK sub-technique tracked in WhisperGraph, serving the Stealth tactic.
Description
Adversaries may use email rules to hide inbound emails in a compromised user's mailbox. Many email clients allow users to create inbox rules for various email functions, including moving emails to other folders, marking emails as read, or deleting emails. Rules may be created or modified within email clients or through external features such as the <code>New-InboxRule</code> or <code>Set-InboxRule</code> [PowerShell](https://attack.mitre.org/techniques/T1059/001) cmdlets on Windows systems.(Citation: Microsoft Inbox Rules)(Citation: MacOS Email Rules)(Citation: Microsoft New-InboxRule)(Citation: Microsoft Set-InboxRule) Adversaries may utilize email rules within a compromised user's mailbox to delete and/or move emails to less noticeable folders. Adversaries may do this to hide security alerts, C2 communication, or responses to [Internal Spearphishing](https://attack.mitre.org/techniques/T1534) emails sent from the compromised account. Any user or administrator within the organization (or adversary with valid credentials) may be able to create rules to automatically move or delete emails. These rules can be abused to impair/delay detection had the email content been immediately seen by a user or defender. Malicious rules commonly filter out emails based on key words (such as <code>malware</code>, <code>suspicious</code>, <code>phish</code>, and <code>hack</code>) found in message bodies and subject lines. (Citation: Microsoft Cloud App Security) In some environments, administrators may be able to enable email 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 automatically modify or delete all emails related to specific topics (such as internal security incident notifications).
Tactics
Related techniques
Parent technique: T1564 · Hide Artifacts
Threat actors observed using this technique
© The MITRE Corporation. This work is reproduced and distributed with the permission of The MITRE Corporation.
Related pages
Pivot from T1564.008 into its tactic, related techniques and the actors that use it.
Queries
Resolves the segment to this technique or tactic.
MATCH (t:ATTACK_PATTERN {name: $id})
RETURN t.id AS id, t.name AS name, t.kind AS kind, t.description AS descriptionRun yourself →The tactic(s) this technique serves.
MATCH (t:ATTACK_PATTERN {name: $id})-[:USES_TACTIC]->(tac:ATTACK_PATTERN)
RETURN tac.id AS id, tac.name AS name
LIMIT 10Run yourself →This id's parent technique, if it is a sub-technique.
MATCH (p:ATTACK_PATTERN {name: $parentId})
RETURN p.id AS id, p.name AS name
LIMIT 1Run yourself →Sub-techniques of this technique, if any.
MATCH (c:ATTACK_PATTERN) WHERE c.id STARTS WITH $subPrefix
RETURN c.id AS id, c.name AS name
ORDER BY c.id
LIMIT 25Run yourself →Threat actors observed using this technique.
MATCH (a:ACTOR)-[:USES_TECHNIQUE]->(t:ATTACK_PATTERN {name: $id})
RETURN a.name AS name
LIMIT 100Run yourself →Or query Whisper from your own LLM workflow via the Whisper MCP server.