New CloudShell User

let match_window = 3m;
AzureActivity
| where ResourceGroup has "cloud-shell"
| where (OperationNameValue =~ "Microsoft.Storage/storageAccounts/listKeys/action")
| where ActivityStatusValue =~ "Success"
| extend TimeKey = bin(TimeGenerated, match_window), AzureIP = CallerIpAddress
| join kind = inner
(AzureActivity
| where ResourceGroup has "cloud-shell"
| where (OperationNameValue =~ "Microsoft.Storage/storageAccounts/write")
| extend TimeKey = bin(TimeGenerated, match_window), UserIP = CallerIpAddress
) on Caller, TimeKey
| summarize count() by TimeKey, Caller, ResourceGroup, SubscriptionId, TenantId, AzureIP, UserIP, HTTPRequest, Type, Properties, CategoryValue, OperationList = strcat(OperationNameValue, ' , ', OperationNameValue1)
| extend Name = tostring(split(Caller,'@',0)[0]), UPNSuffix = tostring(split(Caller,'@',1)[0])

severity: Low
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Azure Activity/Analytic Rules/New-CloudShell-User.yaml
description: |
  'Identifies when a user creates an Azure CloudShell for the first time.
  Monitor this activity to ensure only the expected users are using CloudShell.'  
triggerOperator: gt
queryPeriod: 1d
requiredDataConnectors:
- dataTypes:
  - AzureActivity
  connectorId: AzureActivity
queryFrequency: 1d
triggerThreshold: 0
tactics:
- Execution
query: |
  let match_window = 3m;
  AzureActivity
  | where ResourceGroup has "cloud-shell"
  | where (OperationNameValue =~ "Microsoft.Storage/storageAccounts/listKeys/action")
  | where ActivityStatusValue =~ "Success"
  | extend TimeKey = bin(TimeGenerated, match_window), AzureIP = CallerIpAddress
  | join kind = inner
  (AzureActivity
  | where ResourceGroup has "cloud-shell"
  | where (OperationNameValue =~ "Microsoft.Storage/storageAccounts/write")
  | extend TimeKey = bin(TimeGenerated, match_window), UserIP = CallerIpAddress
  ) on Caller, TimeKey
  | summarize count() by TimeKey, Caller, ResourceGroup, SubscriptionId, TenantId, AzureIP, UserIP, HTTPRequest, Type, Properties, CategoryValue, OperationList = strcat(OperationNameValue, ' , ', OperationNameValue1)
  | extend Name = tostring(split(Caller,'@',0)[0]), UPNSuffix = tostring(split(Caller,'@',1)[0])  
status: Available
kind: Scheduled
relevantTechniques:
- T1059
version: 2.0.2
id: 6d7214d9-4a28-44df-aafb-0910b9e6ae3e
entityMappings:
- fieldMappings:
  - columnName: Name
    identifier: Name
  - columnName: UPNSuffix
    identifier: UPNSuffix
  entityType: Account
- fieldMappings:
  - columnName: UserIP
    identifier: Address
  entityType: IP
name: New CloudShell User

{
  "$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/6d7214d9-4a28-44df-aafb-0910b9e6ae3e')]",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/6d7214d9-4a28-44df-aafb-0910b9e6ae3e')]",
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules",
      "kind": "Scheduled",
      "apiVersion": "2022-11-01-preview",
      "properties": {
        "displayName": "New CloudShell User",
        "description": "'Identifies when a user creates an Azure CloudShell for the first time.\nMonitor this activity to ensure only the expected users are using CloudShell.'\n",
        "severity": "Low",
        "enabled": true,
        "query": "let match_window = 3m;\nAzureActivity\n| where ResourceGroup has \"cloud-shell\"\n| where (OperationNameValue =~ \"Microsoft.Storage/storageAccounts/listKeys/action\")\n| where ActivityStatusValue =~ \"Success\"\n| extend TimeKey = bin(TimeGenerated, match_window), AzureIP = CallerIpAddress\n| join kind = inner\n(AzureActivity\n| where ResourceGroup has \"cloud-shell\"\n| where (OperationNameValue =~ \"Microsoft.Storage/storageAccounts/write\")\n| extend TimeKey = bin(TimeGenerated, match_window), UserIP = CallerIpAddress\n) on Caller, TimeKey\n| summarize count() by TimeKey, Caller, ResourceGroup, SubscriptionId, TenantId, AzureIP, UserIP, HTTPRequest, Type, Properties, CategoryValue, OperationList = strcat(OperationNameValue, ' , ', OperationNameValue1)\n| extend Name = tostring(split(Caller,'@',0)[0]), UPNSuffix = tostring(split(Caller,'@',1)[0])\n",
        "queryFrequency": "P1D",
        "queryPeriod": "P1D",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0,
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "Execution"
        ],
        "techniques": [
          "T1059"
        ],
        "alertRuleTemplateName": "6d7214d9-4a28-44df-aafb-0910b9e6ae3e",
        "customDetails": null,
        "entityMappings": [
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "Name",
                "identifier": "Name"
              },
              {
                "columnName": "UPNSuffix",
                "identifier": "UPNSuffix"
              }
            ]
          },
          {
            "entityType": "IP",
            "fieldMappings": [
              {
                "columnName": "UserIP",
                "identifier": "Address"
              }
            ]
          }
        ],
        "status": "Available",
        "templateVersion": "2.0.2",
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Azure Activity/Analytic Rules/New-CloudShell-User.yaml"
      }
    }
  ]
}