Port scan detected ASIM Network Session schema
| Id | 1da9853f-3dea-4ea9-b7e5-26730da3d537 |
| Rulename | Port scan detected (ASIM Network Session schema) |
| Description | This rule identifies a possible port scan, in which a single source tries to access a large number of different ports is a short time frame. This may indicate that a port scanner is trying to identify open ports in order to penetrate a system. This analytic rule uses ASIM and supports any built-in or custom source that supports the ASIM NetworkSession schema |
| Severity | Medium |
| Tactics | Discovery |
| Techniques | T1046 |
| Required data connectors | AIVectraStream AWSS3 AzureFirewall AzureMonitor(VMInsights) AzureNSG CheckPoint CiscoASA CiscoAsaAma CiscoMeraki Corelight Fortinet MicrosoftSysmonForLinux MicrosoftThreatProtection PaloAltoNetworks SecurityEvents WindowsForwardedEvents WindowsSecurityEvents Zscaler |
| 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/Network Session Essentials/Analytic Rules/PortScan.yaml |
| Version | 1.0.6 |
| Arm template | 1da9853f-3dea-4ea9-b7e5-26730da3d537.json |
let PortScanThreshold = 50;
_Im_NetworkSession
| where ipv4_is_private(SrcIpAddr) == False
| where SrcIpAddr !in ("127.0.0.1", "::1")
| summarize AttemptedPortsCount=dcount(DstPortNumber), AttemptedPorts=make_set(DstPortNumber, 100), ReportedBy=make_set(strcat(EventVendor, "/", EventProduct), 20) by SrcIpAddr, bin(TimeGenerated, 5m)
| where AttemptedPortsCount > PortScanThreshold
status: Available
triggerOperator: gt
triggerThreshold: 0
name: Port scan detected (ASIM Network Session schema)
alertDetailsOverride:
alertDescriptionFormat: A port scan has been performed from address {{SrcIpAddr}} over {{AttemptedPortsCount}} ports within 5 minutes. This may indicate that a [port scanner](https://en.wikipedia.org/wiki/Port_scanner) is trying to identify open ports in order to penetrate a system.
alertDisplayNameFormat: Potential port scan from {{SrcIpAddr}}
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Network Session Essentials/Analytic Rules/PortScan.yaml
queryPeriod: 1h
severity: Medium
tags:
- version: 1.0.0
ParentAlert: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Sophos%20XG%20Firewall/Analytic%20Rules/PortScanDetected.yaml
- SchemaVersion: 0.2.4
Schema: ASimNetworkSessions
kind: Scheduled
entityMappings:
- entityType: IP
fieldMappings:
- columnName: SrcIpAddr
identifier: Address
queryFrequency: 1h
relevantTechniques:
- T1046
requiredDataConnectors:
- dataTypes:
- AWSVPCFlow
connectorId: AWSS3
- dataTypes:
- DeviceNetworkEvents
connectorId: MicrosoftThreatProtection
- dataTypes:
- SecurityEvent
connectorId: SecurityEvents
- dataTypes:
- SecurityEvent
connectorId: WindowsSecurityEvents
- dataTypes:
- WindowsEvent
connectorId: WindowsForwardedEvents
- dataTypes:
- CommonSecurityLog
connectorId: Zscaler
- dataTypes:
- Syslog
connectorId: MicrosoftSysmonForLinux
- dataTypes:
- CommonSecurityLog
connectorId: PaloAltoNetworks
- dataTypes:
- VMConnection
connectorId: AzureMonitor(VMInsights)
- dataTypes:
- AzureDiagnostics
connectorId: AzureFirewall
- dataTypes:
- AzureDiagnostics
connectorId: AzureNSG
- dataTypes:
- CommonSecurityLog
connectorId: CiscoASA
- dataTypes:
- CommonSecurityLog
connectorId: CiscoAsaAma
- dataTypes:
- Corelight_CL
connectorId: Corelight
- dataTypes:
- VectraStream
connectorId: AIVectraStream
- dataTypes:
- CommonSecurityLog
connectorId: CheckPoint
- dataTypes:
- CommonSecurityLog
connectorId: Fortinet
- dataTypes:
- Syslog
- CiscoMerakiNativePoller
connectorId: CiscoMeraki
customDetails:
AttemptedPortsCount: AttemptedPortsCount
description: |
'This rule identifies a possible port scan, in which a single source tries to access a large number of different ports is a short time frame. This may indicate that a [port scanner](https://en.wikipedia.org/wiki/Port_scanner) is trying to identify open ports in order to penetrate a system.
This analytic rule uses [ASIM](https://aka.ms/AboutASIM) and supports any built-in or custom source that supports the ASIM NetworkSession schema'
tactics:
- Discovery
query: |
let PortScanThreshold = 50;
_Im_NetworkSession
| where ipv4_is_private(SrcIpAddr) == False
| where SrcIpAddr !in ("127.0.0.1", "::1")
| summarize AttemptedPortsCount=dcount(DstPortNumber), AttemptedPorts=make_set(DstPortNumber, 100), ReportedBy=make_set(strcat(EventVendor, "/", EventProduct), 20) by SrcIpAddr, bin(TimeGenerated, 5m)
| where AttemptedPortsCount > PortScanThreshold
id: 1da9853f-3dea-4ea9-b7e5-26730da3d537
version: 1.0.6
{
"$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/1da9853f-3dea-4ea9-b7e5-26730da3d537')]",
"kind": "Scheduled",
"name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/1da9853f-3dea-4ea9-b7e5-26730da3d537')]",
"properties": {
"alertDetailsOverride": {
"alertDescriptionFormat": "A port scan has been performed from address {{SrcIpAddr}} over {{AttemptedPortsCount}} ports within 5 minutes. This may indicate that a [port scanner](https://en.wikipedia.org/wiki/Port_scanner) is trying to identify open ports in order to penetrate a system.",
"alertDisplayNameFormat": "Potential port scan from {{SrcIpAddr}}"
},
"alertRuleTemplateName": "1da9853f-3dea-4ea9-b7e5-26730da3d537",
"customDetails": {
"AttemptedPortsCount": "AttemptedPortsCount"
},
"description": "'This rule identifies a possible port scan, in which a single source tries to access a large number of different ports is a short time frame. This may indicate that a [port scanner](https://en.wikipedia.org/wiki/Port_scanner) is trying to identify open ports in order to penetrate a system.\nThis analytic rule uses [ASIM](https://aka.ms/AboutASIM) and supports any built-in or custom source that supports the ASIM NetworkSession schema'\n",
"displayName": "Port scan detected (ASIM Network Session schema)",
"enabled": true,
"entityMappings": [
{
"entityType": "IP",
"fieldMappings": [
{
"columnName": "SrcIpAddr",
"identifier": "Address"
}
]
}
],
"OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Network Session Essentials/Analytic Rules/PortScan.yaml",
"query": "let PortScanThreshold = 50;\n_Im_NetworkSession\n| where ipv4_is_private(SrcIpAddr) == False\n| where SrcIpAddr !in (\"127.0.0.1\", \"::1\")\n| summarize AttemptedPortsCount=dcount(DstPortNumber), AttemptedPorts=make_set(DstPortNumber, 100), ReportedBy=make_set(strcat(EventVendor, \"/\", EventProduct), 20) by SrcIpAddr, bin(TimeGenerated, 5m)\n| where AttemptedPortsCount > PortScanThreshold\n",
"queryFrequency": "PT1H",
"queryPeriod": "PT1H",
"severity": "Medium",
"status": "Available",
"subTechniques": [],
"suppressionDuration": "PT1H",
"suppressionEnabled": false,
"tactics": [
"Discovery"
],
"tags": [
{
"ParentAlert": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Sophos%20XG%20Firewall/Analytic%20Rules/PortScanDetected.yaml",
"version": "1.0.0"
},
{
"Schema": "ASimNetworkSessions",
"SchemaVersion": "0.2.4"
}
],
"techniques": [
"T1046"
],
"templateVersion": "1.0.6",
"triggerOperator": "GreaterThan",
"triggerThreshold": 0
},
"type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
}
]
}