detection.wiki

Detection rules › Sigma

Suspicious Inbox Manipulation Rules

Status
test
Severity
high
Log source
product azure, service riskdetection
Author
Mark Morowczynski '@markmorow', Gloria Lee, '@gleeiamglo'
Source
github.com/SigmaHQ/sigma

Detects suspicious rules that delete or move messages or folders are set on a user's inbox.

MITRE ATT&CK coverage

TacticTechniques
StealthT1140 Deobfuscate/Decode Files or Information

Rule body yaml

title: Suspicious Inbox Manipulation Rules
id: ceb55fd0-726e-4656-bf4e-b585b7f7d572
status: test
description: Detects suspicious rules that delete or move messages or folders are set on a user's inbox.
references:
    - https://learn.microsoft.com/en-us/entra/id-protection/concept-identity-protection-risks#suspicious-inbox-manipulation-rules
    - https://learn.microsoft.com/en-us/entra/architecture/security-operations-user-accounts#unusual-sign-ins
author: Mark Morowczynski '@markmorow', Gloria Lee, '@gleeiamglo'
date: 2023-09-03
tags:
    - attack.stealth
    - attack.t1140
logsource:
    product: azure
    service: riskdetection
detection:
    selection:
        riskEventType: 'mcasSuspiciousInboxManipulationRules'
    condition: selection
falsepositives:
    - Actual mailbox rules that are moving items based on their workflow.
level: high

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
    riskEventType: 'mcasSuspiciousInboxManipulationRules'

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
riskEventTypeeq
  • mcasSuspiciousInboxManipulationRules