GSA - Detect Source IP Scanning Multiple Open Ports

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Id	82cfa6b9-5f7e-4b8b-8b2f-a63f21b7a7d1
Rulename	GSA - Detect Source IP Scanning Multiple Open Ports
Description	Identifies a source IP scanning multiple open ports on Global Secure Access Firewall. This can indicate malicious scanning of ports by an attacker, trying to reveal open ports in the organization that can be compromised for initial access.
Severity	Medium
Tactics	Discovery
Techniques	T1046
Required data connectors	AzureActiveDirectory
Kind	Scheduled
Query frequency	1d
Query period	1d
Trigger threshold	1
Trigger operator	gt
Source Uri	https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Global Secure Access/Analytic Rules/SWG - Source IP Port Scan.yaml
Version	1.0.1
Arm template	82cfa6b9-5f7e-4b8b-8b2f-a63f21b7a7d1.json

KQL

let port_scan_time = 30s;
let min_ports_threshold = 100;
NetworkAccessTraffic
| where TimeGenerated > ago(1d)
| where Action == 'Allowed'
| summarize PortsScanned = dcount(DestinationPort) by SourceIp, DestinationFqdn, bin(TimeGenerated, port_scan_time)
| where PortsScanned > min_ports_threshold
| project SourceIp, PortsScanned, TimeGenerated,DestinationFqdn

YAML

relevantTechniques:
- T1046
name: GSA - Detect Source IP Scanning Multiple Open Ports
Configurable Parameters:
- Port scan time - the time range to look for multiple ports scanned. Default is set to 30 seconds.
- Minimum different ports threshold - alert only if more than this number of ports scanned. Default is set to 100.
requiredDataConnectors:
- dataTypes:
  - EnrichedMicrosoft365AuditLogs
  connectorId: AzureActiveDirectory
entityMappings:
- fieldMappings:
  - identifier: Address
    columnName: SourceIp
  entityType: IP
- fieldMappings:
  - identifier: Url
    columnName: DestinationFqdn
  entityType: URL
triggerThreshold: 1
id: 82cfa6b9-5f7e-4b8b-8b2f-a63f21b7a7d1
tactics:
- Discovery
version: 1.0.1
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Global Secure Access/Analytic Rules/SWG - Source IP Port Scan.yaml
queryPeriod: 1d
kind: Scheduled
queryFrequency: 1d
severity: Medium
status: Available
description: |
    Identifies a source IP scanning multiple open ports on Global Secure Access Firewall. This can indicate malicious scanning of ports by an attacker, trying to reveal open ports in the organization that can be compromised for initial access.
query: |
  let port_scan_time = 30s;
  let min_ports_threshold = 100;
  NetworkAccessTraffic
  | where TimeGenerated > ago(1d)
  | where Action == 'Allowed'
  | summarize PortsScanned = dcount(DestinationPort) by SourceIp, DestinationFqdn, bin(TimeGenerated, port_scan_time)
  | where PortsScanned > min_ports_threshold
  | project SourceIp, PortsScanned, TimeGenerated,DestinationFqdn  
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/82cfa6b9-5f7e-4b8b-8b2f-a63f21b7a7d1')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/82cfa6b9-5f7e-4b8b-8b2f-a63f21b7a7d1')]",
      "properties": {
        "alertRuleTemplateName": "82cfa6b9-5f7e-4b8b-8b2f-a63f21b7a7d1",
        "Configurable Parameters": [
          "Port scan time - the time range to look for multiple ports scanned. Default is set to 30 seconds.",
          "Minimum different ports threshold - alert only if more than this number of ports scanned. Default is set to 100."
        ],
        "customDetails": null,
        "description": "Identifies a source IP scanning multiple open ports on Global Secure Access Firewall. This can indicate malicious scanning of ports by an attacker, trying to reveal open ports in the organization that can be compromised for initial access.\n",
        "displayName": "GSA - Detect Source IP Scanning Multiple Open Ports",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "IP",
            "fieldMappings": [
              {
                "columnName": "SourceIp",
                "identifier": "Address"
              }
            ]
          },
          {
            "entityType": "URL",
            "fieldMappings": [
              {
                "columnName": "DestinationFqdn",
                "identifier": "Url"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Global Secure Access/Analytic Rules/SWG - Source IP Port Scan.yaml",
        "query": "let port_scan_time = 30s;\nlet min_ports_threshold = 100;\nNetworkAccessTraffic\n| where TimeGenerated > ago(1d)\n| where Action == 'Allowed'\n| summarize PortsScanned = dcount(DestinationPort) by SourceIp, DestinationFqdn, bin(TimeGenerated, port_scan_time)\n| where PortsScanned > min_ports_threshold\n| project SourceIp, PortsScanned, TimeGenerated,DestinationFqdn\n",
        "queryFrequency": "P1D",
        "queryPeriod": "P1D",
        "severity": "Medium",
        "status": "Available",
        "subTechniques": [],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "Discovery"
        ],
        "techniques": [
          "T1046"
        ],
        "templateVersion": "1.0.1",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 1
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}