GCP IAM - New Authentication Token for Service Account

GCP_IAM
| where PayloadMethodname =~ 'google.iam.admin.v1.GenerateAccessToken'
| extend result = parse_json(todynamic(PayloadAuthorizationinfo))[0]['granted']
| where result =~ 'true'
| extend service_account = extract(@'serviceAccounts\/(.*?)@', 1, PayloadResponseName)
| project-away result
| extend AccountName = tostring(split(service_account, "@")[0]), AccountUPNSuffix = tostring(split(service_account, "@")[1])

severity: Medium
relevantTechniques:
- T1550
requiredDataConnectors:
- dataTypes:
  - GCP_IAM
  connectorId: GCPIAMDataConnector
status: Available
triggerThreshold: 0
description: |
    'Detects when new authentication token is created for service account.'
triggerOperator: gt
name: GCP IAM - New Authentication Token for Service Account
queryFrequency: 1h
version: 1.0.1
query: |
  GCP_IAM
  | where PayloadMethodname =~ 'google.iam.admin.v1.GenerateAccessToken'
  | extend result = parse_json(todynamic(PayloadAuthorizationinfo))[0]['granted']
  | where result =~ 'true'
  | extend service_account = extract(@'serviceAccounts\/(.*?)@', 1, PayloadResponseName)
  | project-away result
  | extend AccountName = tostring(split(service_account, "@")[0]), AccountUPNSuffix = tostring(split(service_account, "@")[1])  
entityMappings:
- entityType: Account
  fieldMappings:
  - columnName: service_account
    identifier: FullName
  - columnName: AccountName
    identifier: Name
  - columnName: AccountUPNSuffix
    identifier: UPNSuffix
- entityType: IP
  fieldMappings:
  - columnName: SrcIpAddr
    identifier: Address
tactics:
- LateralMovement
queryPeriod: 1h
kind: Scheduled
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/GoogleCloudPlatformIAM/Analytic Rules/GCPIAMNewAuthenticationToken.yaml
id: 80e4db30-5636-4fbd-8816-24c3ded8d243

{
  "$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/80e4db30-5636-4fbd-8816-24c3ded8d243')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/80e4db30-5636-4fbd-8816-24c3ded8d243')]",
      "properties": {
        "alertRuleTemplateName": "80e4db30-5636-4fbd-8816-24c3ded8d243",
        "customDetails": null,
        "description": "'Detects when new authentication token is created for service account.'\n",
        "displayName": "GCP IAM - New Authentication Token for Service Account",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "service_account",
                "identifier": "FullName"
              },
              {
                "columnName": "AccountName",
                "identifier": "Name"
              },
              {
                "columnName": "AccountUPNSuffix",
                "identifier": "UPNSuffix"
              }
            ]
          },
          {
            "entityType": "IP",
            "fieldMappings": [
              {
                "columnName": "SrcIpAddr",
                "identifier": "Address"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/GoogleCloudPlatformIAM/Analytic Rules/GCPIAMNewAuthenticationToken.yaml",
        "query": "GCP_IAM\n| where PayloadMethodname =~ 'google.iam.admin.v1.GenerateAccessToken'\n| extend result = parse_json(todynamic(PayloadAuthorizationinfo))[0]['granted']\n| where result =~ 'true'\n| extend service_account = extract(@'serviceAccounts\\/(.*?)@', 1, PayloadResponseName)\n| project-away result\n| extend AccountName = tostring(split(service_account, \"@\")[0]), AccountUPNSuffix = tostring(split(service_account, \"@\")[1])\n",
        "queryFrequency": "PT1H",
        "queryPeriod": "PT1H",
        "severity": "Medium",
        "status": "Available",
        "subTechniques": [],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "LateralMovement"
        ],
        "techniques": [
          "T1550"
        ],
        "templateVersion": "1.0.1",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}