MFA Spamming followed by Successful login

// Filter for sign-in logs ingested within the last day
SigninLogs
| where ingestion_time() > ago(1d)
// Filter for records with AuthenticationRequirement set to multiFactorAuthentication
| where AuthenticationRequirement == "multiFactorAuthentication"
// Extract information from dynamic columns DeviceDetail and LocationDetails
| extend DeviceDetail = todynamic(DeviceDetail), LocationDetails = todynamic(LocationDetails)
// Extract specific attributes from DeviceDetail and LocationDetails
| extend
      OS = tostring(DeviceDetail.operatingSystem),
      Browser = tostring(DeviceDetail.browser),
      State = tostring(LocationDetails.state),
      City = tostring(LocationDetails.city),
      Region = tostring(LocationDetails.countryOrRegion)
// Expand multi-value property AuthenticationDetails into separate records
| mv-expand todynamic(AuthenticationDetails)
// Parse AuthResult from JSON in AuthenticationDetails and convert to string
| extend AuthResult = tostring(parse_json(AuthenticationDetails).authenticationStepResultDetail)
// Summarize data by aggregating statistics for each user, IP, and AuthResult
| summarize FailedAttempts = countif(AuthResult == "MFA denied; user declined the authentication" or AuthResult == "MFA denied; user did not respond to mobile app notification"), SuccessfulAttempts = countif(AuthResult == "MFA successfully completed"), InvolvedOS = make_set(OS, 5), InvolvedBrowser = make_set(Browser), StartTime = min(TimeGenerated), EndTime = max(TimeGenerated) by UserPrincipalName, IPAddress, State, City, Region
// Calculate AuthenticationWindow by finding time difference between start and end times
| extend AuthenticationWindow = (EndTime - StartTime)
// Filter for records with more than 10 failed attempts in 5-minute window and at least 1 successful attempt
| where FailedAttempts > 10 and AuthenticationWindow <= 5m and SuccessfulAttempts >= 1
// Extract user's name and UPN suffix using split function
| extend Name = tostring(split(UserPrincipalName, '@', 0)[0]), UPNSuffix = tostring(split(UserPrincipalName, '@', 1)[0])

id: a8cc6d5c-4e7e-4b48-b4ac-d8a116c62a8b
triggerThreshold: 0
severity: High
requiredDataConnectors:
- connectorId: AzureActiveDirectory
  dataTypes:
  - SigninLogs
entityMappings:
- fieldMappings:
  - identifier: FullName
    columnName: UserPrincipalName
  - identifier: Name
    columnName: Name
  - identifier: UPNSuffix
    columnName: UPNSuffix
  entityType: Account
- fieldMappings:
  - identifier: Address
    columnName: IPAddress
  entityType: IP
version: 1.0.3
triggerOperator: gt
queryPeriod: 1d
query: |
  // Filter for sign-in logs ingested within the last day
  SigninLogs
  | where ingestion_time() > ago(1d)
  // Filter for records with AuthenticationRequirement set to multiFactorAuthentication
  | where AuthenticationRequirement == "multiFactorAuthentication"
  // Extract information from dynamic columns DeviceDetail and LocationDetails
  | extend DeviceDetail = todynamic(DeviceDetail), LocationDetails = todynamic(LocationDetails)
  // Extract specific attributes from DeviceDetail and LocationDetails
  | extend
        OS = tostring(DeviceDetail.operatingSystem),
        Browser = tostring(DeviceDetail.browser),
        State = tostring(LocationDetails.state),
        City = tostring(LocationDetails.city),
        Region = tostring(LocationDetails.countryOrRegion)
  // Expand multi-value property AuthenticationDetails into separate records
  | mv-expand todynamic(AuthenticationDetails)
  // Parse AuthResult from JSON in AuthenticationDetails and convert to string
  | extend AuthResult = tostring(parse_json(AuthenticationDetails).authenticationStepResultDetail)
  // Summarize data by aggregating statistics for each user, IP, and AuthResult
  | summarize FailedAttempts = countif(AuthResult == "MFA denied; user declined the authentication" or AuthResult == "MFA denied; user did not respond to mobile app notification"), SuccessfulAttempts = countif(AuthResult == "MFA successfully completed"), InvolvedOS = make_set(OS, 5), InvolvedBrowser = make_set(Browser), StartTime = min(TimeGenerated), EndTime = max(TimeGenerated) by UserPrincipalName, IPAddress, State, City, Region
  // Calculate AuthenticationWindow by finding time difference between start and end times
  | extend AuthenticationWindow = (EndTime - StartTime)
  // Filter for records with more than 10 failed attempts in 5-minute window and at least 1 successful attempt
  | where FailedAttempts > 10 and AuthenticationWindow <= 5m and SuccessfulAttempts >= 1
  // Extract user's name and UPN suffix using split function
  | extend Name = tostring(split(UserPrincipalName, '@', 0)[0]), UPNSuffix = tostring(split(UserPrincipalName, '@', 1)[0])  
relevantTechniques:
- T1110
tactics:
- CredentialAccess
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Microsoft Entra ID/Analytic Rules/MFASpammingfollowedbySuccessfullogin.yaml
status: Available
description: |
  'Identifies MFA Spamming followed by Successful logins and by a successful authentication within a given time window,
  Default Failure count is 10 and 1 successful login with default Time Window is 5 minutes.'  
name: MFA Spamming followed by Successful login
kind: Scheduled
queryFrequency: 1d

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "workspace": {
      "type": "String"
    }
  },
  "resources": [
    {
      "apiVersion": "2023-02-01-preview",
      "id": "[concat(resourceId('Microsoft.OperationalInsights/workspaces/providers', parameters('workspace'), 'Microsoft.SecurityInsights'),'/alertRules/a8cc6d5c-4e7e-4b48-b4ac-d8a116c62a8b')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/a8cc6d5c-4e7e-4b48-b4ac-d8a116c62a8b')]",
      "properties": {
        "alertRuleTemplateName": "a8cc6d5c-4e7e-4b48-b4ac-d8a116c62a8b",
        "customDetails": null,
        "description": "'Identifies MFA Spamming followed by Successful logins and by a successful authentication within a given time window,\nDefault Failure count is 10 and 1 successful login with default Time Window is 5 minutes.'\n",
        "displayName": "MFA Spamming followed by Successful login",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "UserPrincipalName",
                "identifier": "FullName"
              },
              {
                "columnName": "Name",
                "identifier": "Name"
              },
              {
                "columnName": "UPNSuffix",
                "identifier": "UPNSuffix"
              }
            ]
          },
          {
            "entityType": "IP",
            "fieldMappings": [
              {
                "columnName": "IPAddress",
                "identifier": "Address"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Microsoft Entra ID/Analytic Rules/MFASpammingfollowedbySuccessfullogin.yaml",
        "query": "// Filter for sign-in logs ingested within the last day\nSigninLogs\n| where ingestion_time() > ago(1d)\n// Filter for records with AuthenticationRequirement set to multiFactorAuthentication\n| where AuthenticationRequirement == \"multiFactorAuthentication\"\n// Extract information from dynamic columns DeviceDetail and LocationDetails\n| extend DeviceDetail = todynamic(DeviceDetail), LocationDetails = todynamic(LocationDetails)\n// Extract specific attributes from DeviceDetail and LocationDetails\n| extend\n      OS = tostring(DeviceDetail.operatingSystem),\n      Browser = tostring(DeviceDetail.browser),\n      State = tostring(LocationDetails.state),\n      City = tostring(LocationDetails.city),\n      Region = tostring(LocationDetails.countryOrRegion)\n// Expand multi-value property AuthenticationDetails into separate records\n| mv-expand todynamic(AuthenticationDetails)\n// Parse AuthResult from JSON in AuthenticationDetails and convert to string\n| extend AuthResult = tostring(parse_json(AuthenticationDetails).authenticationStepResultDetail)\n// Summarize data by aggregating statistics for each user, IP, and AuthResult\n| summarize FailedAttempts = countif(AuthResult == \"MFA denied; user declined the authentication\" or AuthResult == \"MFA denied; user did not respond to mobile app notification\"), SuccessfulAttempts = countif(AuthResult == \"MFA successfully completed\"), InvolvedOS = make_set(OS, 5), InvolvedBrowser = make_set(Browser), StartTime = min(TimeGenerated), EndTime = max(TimeGenerated) by UserPrincipalName, IPAddress, State, City, Region\n// Calculate AuthenticationWindow by finding time difference between start and end times\n| extend AuthenticationWindow = (EndTime - StartTime)\n// Filter for records with more than 10 failed attempts in 5-minute window and at least 1 successful attempt\n| where FailedAttempts > 10 and AuthenticationWindow <= 5m and SuccessfulAttempts >= 1\n// Extract user's name and UPN suffix using split function\n| extend Name = tostring(split(UserPrincipalName, '@', 0)[0]), UPNSuffix = tostring(split(UserPrincipalName, '@', 1)[0])\n",
        "queryFrequency": "P1D",
        "queryPeriod": "P1D",
        "severity": "High",
        "status": "Available",
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "CredentialAccess"
        ],
        "techniques": [
          "T1110"
        ],
        "templateVersion": "1.0.3",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}