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])

kind: Scheduled
severity: Medium
entityMappings:
- fieldMappings:
  - identifier: FullName
    columnName: ActorUPN
  - identifier: Name
    columnName: AccountName
  - identifier: UPNSuffix
    columnName: AccountUPNSuffix
  entityType: Account
- fieldMappings:
  - identifier: Address
    columnName: IpAddress
  entityType: IP
name: Azure DevOps Variable Secret Not Secured
relevantTechniques:
- T1552
triggerOperator: gt
tactics:
- CredentialAccess
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])  
triggerThreshold: 0
status: Available
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.'  
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/AzureDevOpsAuditing/Analytic Rules/ADOSecretNotSecured.yaml
queryFrequency: 1d
queryPeriod: 1d
id: 4ca74dc0-8352-4ac5-893c-73571cc78331
requiredDataConnectors: []
version: 1.0.4

{
  "$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 Rules/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"
    }
  ]
}