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Id2ee727f7-b7c2-4034-b6c9-d245d5a29343
RulenameVMware ESXi - Low temp directory space
DescriptionThis rule is triggered when temp directory space is detected.
SeverityMedium
TacticsImpact
TechniquesT1529
Required data connectorsSyslogAma
KindScheduled
Query frequency1h
Query period1h
Trigger threshold0
Trigger operatorgt
Source Urihttps://github.com/Azure/Azure-Sentinel/blob/master/Solutions/VMWareESXi/Analytic%20Rules/ESXiLowTempDirSpace.yaml
Version1.0.2
Arm template2ee727f7-b7c2-4034-b6c9-d245d5a29343.json
Deploy To Azure
let threshold = 10;
VMwareESXi
| where SyslogMessage has_all ('Temp directory', 'free space')
| extend sp = toreal(extract(@'free space is:\s(\d+)', 1, SyslogMessage)) / 1000000000
| where sp < threshold
| extend h = 'Hypervisor'
| extend HostCustomEntity = h
entityMappings:
- fieldMappings:
  - identifier: FullName
    columnName: HostCustomEntity
  entityType: Host
id: 2ee727f7-b7c2-4034-b6c9-d245d5a29343
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/VMWareESXi/Analytic%20Rules/ESXiLowTempDirSpace.yaml
triggerOperator: gt
tactics:
- Impact
kind: Scheduled
requiredDataConnectors:
- datatypes:
  - Syslog
  connectorId: SyslogAma
queryPeriod: 1h
severity: Medium
relevantTechniques:
- T1529
triggerThreshold: 0
version: 1.0.2
name: VMware ESXi - Low temp directory space
status: Available
query: |
  let threshold = 10;
  VMwareESXi
  | where SyslogMessage has_all ('Temp directory', 'free space')
  | extend sp = toreal(extract(@'free space is:\s(\d+)', 1, SyslogMessage)) / 1000000000
  | where sp < threshold
  | extend h = 'Hypervisor'
  | extend HostCustomEntity = h
description: |
  'This rule is triggered when temp directory space is detected.'
queryFrequency: 1h
{
  "$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/2ee727f7-b7c2-4034-b6c9-d245d5a29343')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/2ee727f7-b7c2-4034-b6c9-d245d5a29343')]",
      "properties": {
        "alertRuleTemplateName": "2ee727f7-b7c2-4034-b6c9-d245d5a29343",
        "customDetails": null,
        "description": "'This rule is triggered when temp directory space is detected.'\n",
        "displayName": "VMware ESXi - Low temp directory space",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "Host",
            "fieldMappings": [
              {
                "columnName": "HostCustomEntity",
                "identifier": "FullName"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/VMWareESXi/Analytic%20Rules/ESXiLowTempDirSpace.yaml",
        "query": "let threshold = 10;\nVMwareESXi\n| where SyslogMessage has_all ('Temp directory', 'free space')\n| extend sp = toreal(extract(@'free space is:\\s(\\d+)', 1, SyslogMessage)) / 1000000000\n| where sp < threshold\n| extend h = 'Hypervisor'\n| extend HostCustomEntity = h\n",
        "queryFrequency": "PT1H",
        "queryPeriod": "PT1H",
        "severity": "Medium",
        "status": "Available",
        "subTechniques": [],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "Impact"
        ],
        "techniques": [
          "T1529"
        ],
        "templateVersion": "1.0.2",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}