MFA Rejected by User

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Id	d99cf5c3-d660-436c-895b-8a8f8448da23
Rulename	MFA Rejected by User
Description	Identifies accurances where a user has rejected an MFA prompt. This could be an indicator that a threat actor has compromised the username and password of this user account and is using it to try and log into the account. Ref : https://docs.microsoft.com/azure/active-directory/fundamentals/security-operations-user-accounts#monitoring-for-failed-unusual-sign-ins
Severity	Medium
Tactics	InitialAccess
Techniques	T1078.004
Required data connectors	AzureActiveDirectory
Kind	Scheduled
Query frequency	1h
Query period	1h
Trigger threshold	0
Trigger operator	gt
Source Uri	https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Azure Active Directory/Analytic Rules/MFARejectedbyUser.yaml
Version	1.0.3
Arm template	d99cf5c3-d660-436c-895b-8a8f8448da23.json

KQL

SigninLogs
| where ResultType == 500121
| extend additionalDetails_ = tostring(Status.additionalDetails)
| where additionalDetails_ =~ "MFA denied; user declined the authentication"
| extend AccountCustomEntity = UserPrincipalName, IPCustomEntity = IPAddress

YAML

name: MFA Rejected by User
query: |
  SigninLogs
  | where ResultType == 500121
  | extend additionalDetails_ = tostring(Status.additionalDetails)
  | where additionalDetails_ =~ "MFA denied; user declined the authentication"
  | extend AccountCustomEntity = UserPrincipalName, IPCustomEntity = IPAddress  
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Azure Active Directory/Analytic Rules/MFARejectedbyUser.yaml
queryFrequency: 1h
triggerThreshold: 0
requiredDataConnectors:
- dataTypes:
  - SigninLogs
  connectorId: AzureActiveDirectory
version: 1.0.3
status: Available
queryPeriod: 1h
id: d99cf5c3-d660-436c-895b-8a8f8448da23
triggerOperator: gt
entityMappings:
- fieldMappings:
  - identifier: FullName
    columnName: AccountCustomEntity
  - identifier: AadUserId
    columnName: UserId
  - identifier: AadTenantId
    columnName: AADTenantId
  entityType: Account
- fieldMappings:
  - identifier: Address
    columnName: IPCustomEntity
  entityType: IP
tags:
- AADSecOpsGuide
relevantTechniques:
- T1078.004
severity: Medium
description: |
  'Identifies accurances where a user has rejected an MFA prompt. This could be an indicator that a threat actor has compromised the username and password of this user account and is using it to try and log into the account.
  Ref : https://docs.microsoft.com/azure/active-directory/fundamentals/security-operations-user-accounts#monitoring-for-failed-unusual-sign-ins'  
kind: Scheduled
tactics:
- InitialAccess

ARM

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "workspace": {
      "type": "String"
    }
  },
  "resources": [
    {
      "id": "[concat(resourceId('Microsoft.OperationalInsights/workspaces/providers', parameters('workspace'), 'Microsoft.SecurityInsights'),'/alertRules/d99cf5c3-d660-436c-895b-8a8f8448da23')]",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/d99cf5c3-d660-436c-895b-8a8f8448da23')]",
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules",
      "kind": "Scheduled",
      "apiVersion": "2022-11-01",
      "properties": {
        "displayName": "MFA Rejected by User",
        "description": "'Identifies accurances where a user has rejected an MFA prompt. This could be an indicator that a threat actor has compromised the username and password of this user account and is using it to try and log into the account.\nRef : https://docs.microsoft.com/azure/active-directory/fundamentals/security-operations-user-accounts#monitoring-for-failed-unusual-sign-ins'\n",
        "severity": "Medium",
        "enabled": true,
        "query": "SigninLogs\n| where ResultType == 500121\n| extend additionalDetails_ = tostring(Status.additionalDetails)\n| where additionalDetails_ =~ \"MFA denied; user declined the authentication\"\n| extend AccountCustomEntity = UserPrincipalName, IPCustomEntity = IPAddress\n",
        "queryFrequency": "PT1H",
        "queryPeriod": "PT1H",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0,
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "InitialAccess"
        ],
        "techniques": [
          "T1078.004"
        ],
        "alertRuleTemplateName": "d99cf5c3-d660-436c-895b-8a8f8448da23",
        "customDetails": null,
        "entityMappings": [
          {
            "fieldMappings": [
              {
                "identifier": "FullName",
                "columnName": "AccountCustomEntity"
              },
              {
                "identifier": "AadUserId",
                "columnName": "UserId"
              },
              {
                "identifier": "AadTenantId",
                "columnName": "AADTenantId"
              }
            ],
            "entityType": "Account"
          },
          {
            "fieldMappings": [
              {
                "identifier": "Address",
                "columnName": "IPCustomEntity"
              }
            ],
            "entityType": "IP"
          }
        ],
        "tags": [
          "AADSecOpsGuide"
        ],
        "status": "Available",
        "templateVersion": "1.0.3",
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Azure Active Directory/Analytic Rules/MFARejectedbyUser.yaml"
      }
    }
  ]
}