Azure DevOps Variable Secret Not Secured

let keywords = dynamic(["secret", "secrets", "password", "PAT", "passwd", "pswd", "pwd", "cred", "creds", "credentials", "credential", "key"]);
ADOAuditLogs
| where OperationName =~ "Library.VariableGroupModified"
| extend Type = tostring(Data.Type)
| extend VariableGroupId = tostring(Data.VariableGroupId)
| extend VariableGroupName = tostring(Data.VariableGroupName)
| mv-expand Data.Variables
| where VariableGroupName has_any (keywords) or Data_Variables has_any (keywords)
| where Type != "AzureKeyVault"
| where Data_Variables !has "IsSecret"
| extend timestamp = TimeGenerated
| extend AccountName = tostring(split(ActorUPN, "@")[0]), AccountUPNSuffix = tostring(split(ActorUPN, "@")[1])

entityMappings:
- entityType: Account
  fieldMappings:
  - columnName: ActorUPN
    identifier: FullName
  - columnName: AccountName
    identifier: Name
  - columnName: AccountUPNSuffix
    identifier: UPNSuffix
- entityType: IP
  fieldMappings:
  - columnName: IpAddress
    identifier: Address
name: Azure DevOps Variable Secret Not Secured
severity: Medium
version: 1.0.4
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/AzureDevOpsAuditing/Analytic%20Rules/ADOSecretNotSecured.yaml
description: |
  'Credentials used in the build process may be stored as Azure DevOps variables. To secure these variables they should be stored in KeyVault or marked as Secrets. 
  This detection looks for new variables added with names that suggest they are credentials but where they are not set as Secrets or stored in KeyVault.'
queryFrequency: 1d
relevantTechniques:
- T1552
kind: Scheduled
triggerOperator: gt
status: Available
tactics:
- CredentialAccess
triggerThreshold: 0
requiredDataConnectors: []
queryPeriod: 1d
query: |
  let keywords = dynamic(["secret", "secrets", "password", "PAT", "passwd", "pswd", "pwd", "cred", "creds", "credentials", "credential", "key"]);
  ADOAuditLogs
  | where OperationName =~ "Library.VariableGroupModified"
  | extend Type = tostring(Data.Type)
  | extend VariableGroupId = tostring(Data.VariableGroupId)
  | extend VariableGroupName = tostring(Data.VariableGroupName)
  | mv-expand Data.Variables
  | where VariableGroupName has_any (keywords) or Data_Variables has_any (keywords)
  | where Type != "AzureKeyVault"
  | where Data_Variables !has "IsSecret"
  | extend timestamp = TimeGenerated
  | extend AccountName = tostring(split(ActorUPN, "@")[0]), AccountUPNSuffix = tostring(split(ActorUPN, "@")[1])
id: 4ca74dc0-8352-4ac5-893c-73571cc78331

{
  "$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/4ca74dc0-8352-4ac5-893c-73571cc78331')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/4ca74dc0-8352-4ac5-893c-73571cc78331')]",
      "properties": {
        "alertRuleTemplateName": "4ca74dc0-8352-4ac5-893c-73571cc78331",
        "customDetails": null,
        "description": "'Credentials used in the build process may be stored as Azure DevOps variables. To secure these variables they should be stored in KeyVault or marked as Secrets. \nThis detection looks for new variables added with names that suggest they are credentials but where they are not set as Secrets or stored in KeyVault.'\n",
        "displayName": "Azure DevOps Variable Secret Not Secured",
        "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%20Rules/ADOSecretNotSecured.yaml",
        "query": "let keywords = dynamic([\"secret\", \"secrets\", \"password\", \"PAT\", \"passwd\", \"pswd\", \"pwd\", \"cred\", \"creds\", \"credentials\", \"credential\", \"key\"]);\nADOAuditLogs\n| where OperationName =~ \"Library.VariableGroupModified\"\n| extend Type = tostring(Data.Type)\n| extend VariableGroupId = tostring(Data.VariableGroupId)\n| extend VariableGroupName = tostring(Data.VariableGroupName)\n| mv-expand Data.Variables\n| where VariableGroupName has_any (keywords) or Data_Variables has_any (keywords)\n| where Type != \"AzureKeyVault\"\n| where Data_Variables !has \"IsSecret\"\n| extend timestamp = TimeGenerated\n| extend AccountName = tostring(split(ActorUPN, \"@\")[0]), AccountUPNSuffix = tostring(split(ActorUPN, \"@\")[1])\n",
        "queryFrequency": "P1D",
        "queryPeriod": "P1D",
        "severity": "Medium",
        "status": "Available",
        "subTechniques": [],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "CredentialAccess"
        ],
        "techniques": [
          "T1552"
        ],
        "templateVersion": "1.0.4",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}