Azure DevOps New Extension Added

let allowed_publishers = dynamic([]);
AzureDevOpsAuditing
| where OperationName =~ "Extension.Installed"
| extend ExtensionName = tostring(Data.ExtensionName)
| extend PublisherName = tostring(Data.PublisherName)
| where PublisherName !in (allowed_publishers)
| project-reorder TimeGenerated, OperationName, ExtensionName, PublisherName, ActorUPN, IpAddress, UserAgent, ScopeDisplayName, Data
| extend timestamp = TimeGenerated
| extend AccountName = tostring(split(ActorUPN, "@")[0]), AccountUPNSuffix = tostring(split(ActorUPN, "@")[1])

relevantTechniques:
- T1505
name: Azure DevOps New Extension Added
requiredDataConnectors: []
entityMappings:
- fieldMappings:
  - identifier: FullName
    columnName: ActorUPN
  - identifier: Name
    columnName: AccountName
  - identifier: UPNSuffix
    columnName: AccountUPNSuffix
  entityType: Account
- fieldMappings:
  - identifier: Address
    columnName: IpAddress
  entityType: IP
triggerThreshold: 0
id: bf07ca9c-e408-443a-8939-6860a45a929e
tactics:
- Persistence
version: 1.0.3
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/AzureDevOpsAuditing/Analytic Rules/ADONewExtensionAdded.yaml
queryPeriod: 1d
kind: Scheduled
queryFrequency: 1d
severity: Low
status: Available
description: |
  'Extensions add additional features to Azure DevOps. An attacker could use a malicious extension to conduct malicious activity. 
  This query looks for new extensions that are not from a configurable list of approved publishers.'  
query: |
  let allowed_publishers = dynamic([]);
  AzureDevOpsAuditing
  | where OperationName =~ "Extension.Installed"
  | extend ExtensionName = tostring(Data.ExtensionName)
  | extend PublisherName = tostring(Data.PublisherName)
  | where PublisherName !in (allowed_publishers)
  | project-reorder TimeGenerated, OperationName, ExtensionName, PublisherName, ActorUPN, IpAddress, UserAgent, ScopeDisplayName, Data
  | extend timestamp = TimeGenerated
  | extend AccountName = tostring(split(ActorUPN, "@")[0]), AccountUPNSuffix = tostring(split(ActorUPN, "@")[1])  
triggerOperator: gt

{
  "$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/bf07ca9c-e408-443a-8939-6860a45a929e')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/bf07ca9c-e408-443a-8939-6860a45a929e')]",
      "properties": {
        "alertRuleTemplateName": "bf07ca9c-e408-443a-8939-6860a45a929e",
        "customDetails": null,
        "description": "'Extensions add additional features to Azure DevOps. An attacker could use a malicious extension to conduct malicious activity. \nThis query looks for new extensions that are not from a configurable list of approved publishers.'\n",
        "displayName": "Azure DevOps New Extension Added",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "ActorUPN",
                "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/Solutions/AzureDevOpsAuditing/Analytic Rules/ADONewExtensionAdded.yaml",
        "query": "let allowed_publishers = dynamic([]);\nAzureDevOpsAuditing\n| where OperationName =~ \"Extension.Installed\"\n| extend ExtensionName = tostring(Data.ExtensionName)\n| extend PublisherName = tostring(Data.PublisherName)\n| where PublisherName !in (allowed_publishers)\n| project-reorder TimeGenerated, OperationName, ExtensionName, PublisherName, ActorUPN, IpAddress, UserAgent, ScopeDisplayName, Data\n| extend timestamp = TimeGenerated\n| extend AccountName = tostring(split(ActorUPN, \"@\")[0]), AccountUPNSuffix = tostring(split(ActorUPN, \"@\")[1])\n",
        "queryFrequency": "P1D",
        "queryPeriod": "P1D",
        "severity": "Low",
        "status": "Available",
        "subTechniques": [],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "Persistence"
        ],
        "techniques": [
          "T1505"
        ],
        "templateVersion": "1.0.3",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}