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
id: 2ee727f7-b7c2-4034-b6c9-d245d5a29343
triggerOperator: gt
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/VMWareESXi/Analytic Rules/ESXiLowTempDirSpace.yaml
requiredDataConnectors:
- datatypes:
- Syslog
connectorId: SyslogAma
description: |
'This rule is triggered when temp directory space is detected.'
severity: Medium
queryPeriod: 1h
kind: Scheduled
tactics:
- Impact
queryFrequency: 1h
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
version: 1.0.2
triggerThreshold: 0
name: VMware ESXi - Low temp directory space
entityMappings:
- entityType: Host
fieldMappings:
- columnName: HostCustomEntity
identifier: FullName
status: Available
relevantTechniques:
- T1529
{
"$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 Rules/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"
}
]
}