Corelight - Forced External Outbound SMB | Microsoft Sentinel Analytic Rules

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Id	73f23aa2-5cc4-4507-940b-75c9092e9e01
Rulename	Corelight - Forced External Outbound SMB
Description	Detects SMB requests that originate internally and communicate with an external IP address.
Severity	Medium
Tactics	CredentialAccess
Techniques	T1187
Required data connectors	Corelight
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/Corelight/Analytic%20Rules/CorelightForcedExternalOutboundSMB.yaml
Version	2.1.0
Arm template	73f23aa2-5cc4-4507-940b-75c9092e9e01.json

KQL

union corelight_conn, corelight_conn_red
| where local_orig == true
| where local_resp == false
| where history hasprefix 'Sh' and service hasprefix 'smb'

YAML

id: 73f23aa2-5cc4-4507-940b-75c9092e9e01
severity: Medium
queryPeriod: 1h
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Corelight/Analytic%20Rules/CorelightForcedExternalOutboundSMB.yaml
kind: Scheduled
requiredDataConnectors:
- dataTypes:
  - Corelight_v2_conn
  - Corelight_v2_conn_red
  - corelight_conn
  - corelight_conn_red
  connectorId: Corelight
triggerThreshold: 0
status: Available
relevantTechniques:
- T1187
entityMappings:
- fieldMappings:
  - columnName: id_orig_h
    identifier: Address
  entityType: IP
name: Corelight - Forced External Outbound SMB
query: |
  union corelight_conn, corelight_conn_red
  | where local_orig == true
  | where local_resp == false
  | where history hasprefix 'Sh' and service hasprefix 'smb'
queryFrequency: 1h
version: 2.1.0
description: |
  'Detects SMB requests that originate internally and communicate with an external IP address.'
tactics:
- CredentialAccess
triggerOperator: gt

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/73f23aa2-5cc4-4507-940b-75c9092e9e01')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/73f23aa2-5cc4-4507-940b-75c9092e9e01')]",
      "properties": {
        "alertRuleTemplateName": "73f23aa2-5cc4-4507-940b-75c9092e9e01",
        "customDetails": null,
        "description": "'Detects SMB requests that originate internally and communicate with an external IP address.'\n",
        "displayName": "Corelight - Forced External Outbound SMB",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "IP",
            "fieldMappings": [
              {
                "columnName": "id_orig_h",
                "identifier": "Address"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Corelight/Analytic%20Rules/CorelightForcedExternalOutboundSMB.yaml",
        "query": "union corelight_conn, corelight_conn_red\n| where local_orig == true\n| where local_resp == false\n| where history hasprefix 'Sh' and service hasprefix 'smb'\n",
        "queryFrequency": "PT1H",
        "queryPeriod": "PT1H",
        "severity": "Medium",
        "status": "Available",
        "subTechniques": [],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "CredentialAccess"
        ],
        "techniques": [
          "T1187"
        ],
        "templateVersion": "2.1.0",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}