GCP IAM - New Authentication Token for Service Account

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Id	80e4db30-5636-4fbd-8816-24c3ded8d243
Rulename	GCP IAM - New Authentication Token for Service Account
Description	Detects when new authentication token is created for service account.
Severity	Medium
Tactics	LateralMovement
Techniques	T1550
Required data connectors	GCPIAMDataConnector
Kind	Scheduled
Query frequency	1h
Query period	1h
Trigger threshold	0
Trigger operator	gt
Source Uri	https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/GoogleCloudPlatformIAM/Analytic%20Rules/GCPIAMNewAuthenticationToken.yaml
Version	1.0.2
Arm template	80e4db30-5636-4fbd-8816-24c3ded8d243.json

KQL

GCP_IAM
| where PayloadMethodname in ('GenerateAccessToken', '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])

YAML

name: GCP IAM - New Authentication Token for Service Account
triggerOperator: gt
query: |
  GCP_IAM
  | where PayloadMethodname in ('GenerateAccessToken', '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])
queryFrequency: 1h
description: |
  'Detects when new authentication token is created for service account.'
id: 80e4db30-5636-4fbd-8816-24c3ded8d243
triggerThreshold: 0
queryPeriod: 1h
version: 1.0.2
kind: Scheduled
status: Available
severity: Medium
requiredDataConnectors:
- connectorId: GCPIAMDataConnector
  dataTypes:
  - GCP_IAM
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/GoogleCloudPlatformIAM/Analytic%20Rules/GCPIAMNewAuthenticationToken.yaml
relevantTechniques:
- T1550
tactics:
- LateralMovement
entityMappings:
- fieldMappings:
  - identifier: FullName
    columnName: service_account
  - identifier: Name
    columnName: AccountName
  - identifier: UPNSuffix
    columnName: AccountUPNSuffix
  entityType: Account
- fieldMappings:
  - identifier: Address
    columnName: SrcIpAddr
  entityType: IP

ARM

{
  "$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%20Rules/GCPIAMNewAuthenticationToken.yaml",
        "query": "GCP_IAM\n| where PayloadMethodname in ('GenerateAccessToken', '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": "1.0.2",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}