Detection rules › Sigma
Multifactor Authentication Denied
User has indicated they haven't instigated the MFA prompt and could indicate an attacker has the password for the account.
Known false positives
- Users actually login but miss-click into the Deny button when MFA prompt.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Initial Access | |
| Persistence | |
| Privilege Escalation | |
| Stealth | |
| Credential Access |
Telemetry coverage
| Platform | Record / event type |
|---|---|
| Entra ID | SigninLogs sign-in event: Sign-in recording an authentication requirement |
Rule body
title: Multifactor Authentication Denied
id: e40f4962-b02b-4192-9bfe-245f7ece1f99
status: test
description: User has indicated they haven't instigated the MFA prompt and could indicate an attacker has the password for the account.
references:
- https://www.microsoft.com/security/blog/2022/03/22/dev-0537-criminal-actor-targeting-organizations-for-data-exfiltration-and-destruction/
author: AlertIQ
date: 2022-03-24
tags:
- attack.privilege-escalation
- attack.persistence
- attack.initial-access
- attack.credential-access
- attack.stealth
- attack.t1078.004
- attack.t1110
- attack.t1621
logsource:
product: azure
service: signinlogs
detection:
selection:
AuthenticationRequirement: 'multiFactorAuthentication'
Status|contains: 'MFA Denied'
condition: selection
falsepositives:
- Users actually login but miss-click into the Deny button when MFA prompt.
level: medium
Stages and Predicates
Stage 0: condition
selectionStage 1: selection
selection:
AuthenticationRequirement: 'multiFactorAuthentication'
Status|contains: 'MFA Denied'
Indicators
These rows show field, operator, and value matches.
| Field | Kind | Values | Search |
|---|---|---|---|
AuthenticationRequirement | eq |
| field:"azure_ad::authentication_requirement" kind:eq value:"multiFactorAuthentication" |
Status | match |
| field:"Status" kind:match value:"MFA Denied" |