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

{
  "$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"
    }
  ]
}