Privileged User Logon from new ASN

let admins=(IdentityInfo
  | where AssignedRoles contains "admin" or GroupMembership has "Admin"
  | summarize by tolower(AccountUPN));
  let known_asns = (
  SigninLogs
  | where TimeGenerated between(ago(14d)..ago(1d))
  | where ResultType == 0
  | summarize by AutonomousSystemNumber);
  SigninLogs
  | where TimeGenerated > ago(1d)
  | where ResultType == 0
  | where tolower(UserPrincipalName) in (admins)
  | where AutonomousSystemNumber !in (known_asns)
  | project-reorder TimeGenerated, UserPrincipalName, UserAgent, IPAddress, AutonomousSystemNumber
  | extend AccountName = tostring(split(UserPrincipalName, "@")[0]), AccountUPNSuffix = tostring(split(UserPrincipalName, "@")[1])

severity: Medium
relevantTechniques:
- T1078.004
requiredDataConnectors:
- dataTypes:
  - SigninLogs
  connectorId: AzureActiveDirectory
- dataTypes:
  - BehaviorAnalytics
  connectorId: BehaviorAnalytics
- dataTypes:
  - IdentityInfo
  connectorId: BehaviorAnalytics
triggerThreshold: 0
description: |
  'Detects a successful logon by a privileged account from an ASN not logged in from in the last 14 days.
    Monitor these logons to ensure they are legitimate and identify if there are any similar sign ins.'  
triggerOperator: gt
name: Privileged User Logon from new ASN
queryFrequency: 1d
version: 1.0.6
kind: Scheduled
query: |
  let admins=(IdentityInfo
    | where AssignedRoles contains "admin" or GroupMembership has "Admin"
    | summarize by tolower(AccountUPN));
    let known_asns = (
    SigninLogs
    | where TimeGenerated between(ago(14d)..ago(1d))
    | where ResultType == 0
    | summarize by AutonomousSystemNumber);
    SigninLogs
    | where TimeGenerated > ago(1d)
    | where ResultType == 0
    | where tolower(UserPrincipalName) in (admins)
    | where AutonomousSystemNumber !in (known_asns)
    | project-reorder TimeGenerated, UserPrincipalName, UserAgent, IPAddress, AutonomousSystemNumber
    | extend AccountName = tostring(split(UserPrincipalName, "@")[0]), AccountUPNSuffix = tostring(split(UserPrincipalName, "@")[1])  
entityMappings:
- entityType: Account
  fieldMappings:
  - columnName: UserPrincipalName
    identifier: FullName
  - columnName: AccountName
    identifier: Name
  - columnName: AccountUPNSuffix
    identifier: UPNSuffix
- entityType: IP
  fieldMappings:
  - columnName: IPAddress
    identifier: Address
tactics:
- DefenseEvasion
metadata:
  support:
    tier: Community
  author:
    name: Microsoft Security Research
  source:
    kind: Community
  categories:
    domains:
    - Identity
    - Security - Others
queryPeriod: 7d
tags:
- AADSecOpsGuide
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Detections/SigninLogs/PrivilegedUserLogonfromnewASN.yaml
id: 55073036-bb86-47d3-a85a-b113ac3d9396

{
  "$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/55073036-bb86-47d3-a85a-b113ac3d9396')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/55073036-bb86-47d3-a85a-b113ac3d9396')]",
      "properties": {
        "alertRuleTemplateName": "55073036-bb86-47d3-a85a-b113ac3d9396",
        "customDetails": null,
        "description": "'Detects a successful logon by a privileged account from an ASN not logged in from in the last 14 days.\n  Monitor these logons to ensure they are legitimate and identify if there are any similar sign ins.'\n",
        "displayName": "Privileged User Logon from new ASN",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "UserPrincipalName",
                "identifier": "FullName"
              },
              {
                "columnName": "AccountName",
                "identifier": "Name"
              },
              {
                "columnName": "AccountUPNSuffix",
                "identifier": "UPNSuffix"
              }
            ]
          },
          {
            "entityType": "IP",
            "fieldMappings": [
              {
                "columnName": "IPAddress",
                "identifier": "Address"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Detections/SigninLogs/PrivilegedUserLogonfromnewASN.yaml",
        "query": "let admins=(IdentityInfo\n  | where AssignedRoles contains \"admin\" or GroupMembership has \"Admin\"\n  | summarize by tolower(AccountUPN));\n  let known_asns = (\n  SigninLogs\n  | where TimeGenerated between(ago(14d)..ago(1d))\n  | where ResultType == 0\n  | summarize by AutonomousSystemNumber);\n  SigninLogs\n  | where TimeGenerated > ago(1d)\n  | where ResultType == 0\n  | where tolower(UserPrincipalName) in (admins)\n  | where AutonomousSystemNumber !in (known_asns)\n  | project-reorder TimeGenerated, UserPrincipalName, UserAgent, IPAddress, AutonomousSystemNumber\n  | extend AccountName = tostring(split(UserPrincipalName, \"@\")[0]), AccountUPNSuffix = tostring(split(UserPrincipalName, \"@\")[1])\n",
        "queryFrequency": "P1D",
        "queryPeriod": "P7D",
        "severity": "Medium",
        "subTechniques": [
          "T1078.004"
        ],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "DefenseEvasion"
        ],
        "tags": [
          "AADSecOpsGuide"
        ],
        "techniques": [
          "T1078"
        ],
        "templateVersion": "1.0.6",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}