Detection rules › Sigma

Multifactor Authentication Interrupted

Status
test
Severity
medium
Log source
product azure, service signinlogs
Author
AlertIQ
Source
github.com/SigmaHQ/sigma

Identifies user login with multifactor authentication failures, which might be an indication an attacker has the password for the account but can't pass the MFA challenge.

MITRE ATT&CK coverage

Rules detecting the same action

Other rules on this platform that filter on the same API call or operation.

Rule body yaml

title: Multifactor Authentication Interrupted
id: 5496ff55-42ec-4369-81cb-00f417029e25
status: test
description: Identifies user login with multifactor authentication failures, which might be an indication an attacker has the password for the account but can't pass the MFA challenge.
references:
    - https://learn.microsoft.com/en-us/entra/architecture/security-operations-privileged-accounts
author: AlertIQ
date: 2021-10-10
modified: 2022-12-18
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_50074:
        ResultType: 50074
        ResultDescription|contains: 'Strong Auth required'
    selection_500121:
        ResultType: 500121
        ResultDescription|contains: 'Authentication failed during strong authentication request'
    condition: 1 of selection_*
falsepositives:
    - Unknown
level: medium

Stages and Predicates

Stage 0: condition

1 of selection_*

Stage 1: selection_50074

selection_50074:
    ResultType: 50074
    ResultDescription|contains: 'Strong Auth required'

Stage 2: selection_500121

selection_500121:
    ResultType: 500121
    ResultDescription|contains: 'Authentication failed during strong authentication request'

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
ResultDescriptionmatch
  • Authentication failed during strong authentication request
  • Strong Auth required
ResultTypeeq
  • 500121
  • 50074