H3XAOperational intelligence
Live analytical pictureEvidence before assessment
TypeTechnique
External ID—
First seen2026-08-14
Last seen2026-08-14

Confidence

—

Adversaries may abuse Microsoft Outlook rules to obtain persistence on a compromised system. Outlook rules allow a user to define automated behavior to manage email messages. A benign rule might, for example, automatically move an email to a particular folder in Outlook if it contains specific words from a specific sender. Malicious Outlook rules can be created that can trigger code execution when an adversary sends a specifically crafted email to that user.(Citation: SilentBreak Outlook Rules) Once malicious rules have been added to the user’s mailbox, they will be loaded when Outlook is started. Malicious rules will execute when an adversary sends a specifically crafted email to the user.(Citation: SilentBreak Outlook Rules)

4 recorded

Relationships

mitigatesMitigation
mitigatesMitigation
subtechnique-ofTechnique
uses
from Ruler
Tool
5 external

References

mitre-attack
T1137.005
open
Pfammatter - Hidden Inbox Rules
https://blog.compass-security.com/2018/09/hidden-inbox-rules-in-microsoft-exchange/
open
Microsoft Detect Outlook Forms
https://docs.microsoft.com/en-us/office365/securitycompliance/detect-and-remediate-outlook-rules-forms-attack
open
SilentBreak Outlook Rules
https://silentbreaksecurity.com/malicious-outlook-rules/
open
SensePost NotRuler
https://github.com/sensepost/notruler
open