Potential Password Spray Attack Uses Authentication Normalization

let FailureThreshold = 15;
imAuthentication
| where EventType== 'Logon' and  EventResult== 'Failure'
// reason: creds 
| where EventResultDetails in ('No such user or password', 'Incorrect password')
| summarize UserCount=dcount(TargetUserId), Vendors=make_set(EventVendor), Products=make_set(EventVendor)
  , Users = make_set(TargetUserId,100) 
    by SrcDvcIpAddr, SrcGeoCountry, bin(TimeGenerated, 5m)
| where UserCount > FailureThreshold

version: 1.1.3
relevantTechniques:
- T1110
id: 6a2e2ff4-5568-475e-bef2-b95f12b9367b
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Detections/ASimAuthentication/imAuthPasswordSpray.yaml
tags:
- version: 1.0.0
  Id: e27dd7e5-4367-4c40-a2b7-fcd7e7a8a508
- SchemaVersion: 0.1.0
  Schema: ASIMAuthentication
requiredDataConnectors: []
tactics:
- CredentialAccess
name: Potential Password Spray Attack (Uses Authentication Normalization)
queryPeriod: 1h
entityMappings:
- fieldMappings:
  - identifier: Address
    columnName: SrcDvcIpAddr
  entityType: IP
queryFrequency: 1h
triggerThreshold: 0
severity: Medium
metadata:
  categories:
    domains:
    - Security - Others
    - Identity
  support:
    tier: Community
  source:
    kind: Community
  author:
    name: Ofer Shezaf
triggerOperator: gt
kind: Scheduled
query: |
  let FailureThreshold = 15;
  imAuthentication
  | where EventType== 'Logon' and  EventResult== 'Failure'
  // reason: creds 
  | where EventResultDetails in ('No such user or password', 'Incorrect password')
  | summarize UserCount=dcount(TargetUserId), Vendors=make_set(EventVendor), Products=make_set(EventVendor)
    , Users = make_set(TargetUserId,100) 
      by SrcDvcIpAddr, SrcGeoCountry, bin(TimeGenerated, 5m)
  | where UserCount > FailureThreshold
description: |
  'This query searches for failed attempts to log in from more than 15 various users within a 5 minute timeframe from the same source. This is a potential indication of a password spray attack
   To use this analytics rule, make sure you have deployed the [ASIM normalization parsers](https://aka.ms/ASimAuthentication)'

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "workspace": {
      "type": "String"
    }
  },
  "resources": [
    {
      "apiVersion": "2024-01-01-preview",
      "id": "[concat(resourceId('Microsoft.OperationalInsights/workspaces/providers', parameters('workspace'), 'Microsoft.SecurityInsights'),'/alertRules/6a2e2ff4-5568-475e-bef2-b95f12b9367b')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/6a2e2ff4-5568-475e-bef2-b95f12b9367b')]",
      "properties": {
        "alertRuleTemplateName": "6a2e2ff4-5568-475e-bef2-b95f12b9367b",
        "customDetails": null,
        "description": "'This query searches for failed attempts to log in from more than 15 various users within a 5 minute timeframe from the same source. This is a potential indication of a password spray attack\n To use this analytics rule, make sure you have deployed the [ASIM normalization parsers](https://aka.ms/ASimAuthentication)'\n",
        "displayName": "Potential Password Spray Attack (Uses Authentication Normalization)",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "IP",
            "fieldMappings": [
              {
                "columnName": "SrcDvcIpAddr",
                "identifier": "Address"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Detections/ASimAuthentication/imAuthPasswordSpray.yaml",
        "query": "let FailureThreshold = 15;\nimAuthentication\n| where EventType== 'Logon' and  EventResult== 'Failure'\n// reason: creds \n| where EventResultDetails in ('No such user or password', 'Incorrect password')\n| summarize UserCount=dcount(TargetUserId), Vendors=make_set(EventVendor), Products=make_set(EventVendor)\n  , Users = make_set(TargetUserId,100) \n    by SrcDvcIpAddr, SrcGeoCountry, bin(TimeGenerated, 5m)\n| where UserCount > FailureThreshold\n",
        "queryFrequency": "PT1H",
        "queryPeriod": "PT1H",
        "severity": "Medium",
        "subTechniques": [],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "CredentialAccess"
        ],
        "tags": [
          {
            "Id": "e27dd7e5-4367-4c40-a2b7-fcd7e7a8a508",
            "version": "1.0.0"
          },
          {
            "Schema": "ASIMAuthentication",
            "SchemaVersion": "0.1.0"
          }
        ],
        "techniques": [
          "T1110"
        ],
        "templateVersion": "1.1.3",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}