Microsoft Sentinel Analytic Rules
cloudbrothers.infoAzure Sentinel RepoToggle Dark/Light/Auto modeToggle Dark/Light/Auto modeToggle Dark/Light/Auto modeBack to homepage

Palo Alto - possible internal to external port scanning

Back
Id5b72f527-e3f6-4a00-9908-8e4fee14da9f
RulenamePalo Alto - possible internal to external port scanning
DescriptionIdentifies a list of internal Source IPs (10.x.x.x Hosts) that have triggered 10 or more non-graceful tcp server resets from one or more Destination IPs which

results in an “ApplicationProtocol = incomplete” designation. The server resets coupled with an “Incomplete” ApplicationProtocol designation can be an indication

of internal to external port scanning or probing attack.

References: https://knowledgebase.paloaltonetworks.com/KCSArticleDetail?id=kA10g000000ClUvCAK and

https://knowledgebase.paloaltonetworks.com/KCSArticleDetail?id=kA10g000000ClTaCAK
SeverityLow
TacticsDiscovery
TechniquesT1046
Required data connectorsPaloAltoNetworks
PaloAltoNetworksAma
KindScheduled
Query frequency1h
Query period1h
Trigger threshold0
Trigger operatorgt
Source Urihttps://github.com/Azure/Azure-Sentinel/blob/master/Solutions/PaloAlto-PAN-OS/Analytic Rules/PaloAlto-PortScanning.yaml
Version1.0.3
Arm template5b72f527-e3f6-4a00-9908-8e4fee14da9f.json
Deploy To Azure
CommonSecurityLog
| where isnotempty(DestinationPort) and DeviceAction !in ("reset-both", "deny")
// filter out common usage ports. Add ports that are legitimate for your environment
| where DestinationPort !in ("443", "53", "389", "80", "0", "880", "8888", "8080")
| where ApplicationProtocol == "incomplete"
// filter out IANA ephemeral or negotiated ports as per https://en.wikipedia.org/wiki/Ephemeral_port
| where DestinationPort !between (toint(49512) .. toint(65535))
| where Computer != ""
| where DestinationIP !startswith "10."
| extend Reason = coalesce(
                              column_ifexists("Reason", ""),
                              extract("reason=(.+?)(;|$)", 1, AdditionalExtensions),
                              ""
                          )
// Filter out any graceful reset reasons of AGED OUT which occurs when a TCP session closes with a FIN due to aging out.
| where Reason !has "aged-out"
// Filter out any TCP FIN which occurs when a TCP FIN is used to gracefully close half or both sides of a connection.
| where Reason !has "tcp-fin"
// Uncomment one of the following where clauses to trigger on specific TCP reset reasons
// See Palo Alto article for details - https://knowledgebase.paloaltonetworks.com/KCSArticleDetail?id=kA10g000000ClUvCAK
// TCP RST-server - Occurs when the server sends a TCP reset to the client
// | where AdditionalExtensions has "reason=tcp-rst-from-server"
// TCP RST-client - Occurs when the client sends a TCP reset to the server
// | where AdditionalExtensions has "reason=tcp-rst-from-client"
// Already performed
//| extend reason = tostring(split(AdditionalExtensions, ";")[3])
| summarize StartTimeUtc = min(TimeGenerated), EndTimeUtc = max(TimeGenerated), count() by DeviceName, SourceUserID, SourceIP, ApplicationProtocol, Reason, DestinationPort, Protocol, DeviceVendor, DeviceProduct, DeviceAction, DestinationIP
| where count_ >= 10
| summarize StartTimeUtc = min(StartTimeUtc), EndTimeUtc = max(EndTimeUtc), makeset(DestinationIP), totalcount = sum(count_) by DeviceName, SourceUserID, SourceIP, ApplicationProtocol, Reason, DestinationPort, Protocol, DeviceVendor, DeviceProduct, DeviceAction
| extend timestamp = StartTimeUtc, IPCustomEntity = SourceIP, AccountCustomEntity = SourceUserID, HostCustomEntity = DeviceName
name: Palo Alto - possible internal to external port scanning
triggerOperator: gt
status: Available
relevantTechniques:
- T1046
query: |
  CommonSecurityLog
  | where isnotempty(DestinationPort) and DeviceAction !in ("reset-both", "deny")
  // filter out common usage ports. Add ports that are legitimate for your environment
  | where DestinationPort !in ("443", "53", "389", "80", "0", "880", "8888", "8080")
  | where ApplicationProtocol == "incomplete"
  // filter out IANA ephemeral or negotiated ports as per https://en.wikipedia.org/wiki/Ephemeral_port
  | where DestinationPort !between (toint(49512) .. toint(65535))
  | where Computer != ""
  | where DestinationIP !startswith "10."
  | extend Reason = coalesce(
                                column_ifexists("Reason", ""),
                                extract("reason=(.+?)(;|$)", 1, AdditionalExtensions),
                                ""
                            )
  // Filter out any graceful reset reasons of AGED OUT which occurs when a TCP session closes with a FIN due to aging out.
  | where Reason !has "aged-out"
  // Filter out any TCP FIN which occurs when a TCP FIN is used to gracefully close half or both sides of a connection.
  | where Reason !has "tcp-fin"
  // Uncomment one of the following where clauses to trigger on specific TCP reset reasons
  // See Palo Alto article for details - https://knowledgebase.paloaltonetworks.com/KCSArticleDetail?id=kA10g000000ClUvCAK
  // TCP RST-server - Occurs when the server sends a TCP reset to the client
  // | where AdditionalExtensions has "reason=tcp-rst-from-server"
  // TCP RST-client - Occurs when the client sends a TCP reset to the server
  // | where AdditionalExtensions has "reason=tcp-rst-from-client"
  // Already performed
  //| extend reason = tostring(split(AdditionalExtensions, ";")[3])
  | summarize StartTimeUtc = min(TimeGenerated), EndTimeUtc = max(TimeGenerated), count() by DeviceName, SourceUserID, SourceIP, ApplicationProtocol, Reason, DestinationPort, Protocol, DeviceVendor, DeviceProduct, DeviceAction, DestinationIP
  | where count_ >= 10
  | summarize StartTimeUtc = min(StartTimeUtc), EndTimeUtc = max(EndTimeUtc), makeset(DestinationIP), totalcount = sum(count_) by DeviceName, SourceUserID, SourceIP, ApplicationProtocol, Reason, DestinationPort, Protocol, DeviceVendor, DeviceProduct, DeviceAction
  | extend timestamp = StartTimeUtc, IPCustomEntity = SourceIP, AccountCustomEntity = SourceUserID, HostCustomEntity = DeviceName  
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/PaloAlto-PAN-OS/Analytic Rules/PaloAlto-PortScanning.yaml
description: |
  'Identifies a list of internal Source IPs (10.x.x.x Hosts) that have triggered 10 or more non-graceful tcp server resets from one or more Destination IPs which
  results in an "ApplicationProtocol = incomplete" designation. The server resets coupled with an "Incomplete" ApplicationProtocol designation can be an indication
  of internal to external port scanning or probing attack.
  References: https://knowledgebase.paloaltonetworks.com/KCSArticleDetail?id=kA10g000000ClUvCAK and
  https://knowledgebase.paloaltonetworks.com/KCSArticleDetail?id=kA10g000000ClTaCAK'  
triggerThreshold: 0
id: 5b72f527-e3f6-4a00-9908-8e4fee14da9f
kind: Scheduled
severity: Low
version: 1.0.3
entityMappings:
- fieldMappings:
  - identifier: FullName
    columnName: AccountCustomEntity
  entityType: Account
- fieldMappings:
  - identifier: FullName
    columnName: HostCustomEntity
  entityType: Host
- fieldMappings:
  - identifier: Address
    columnName: IPCustomEntity
  entityType: IP
queryFrequency: 1h
queryPeriod: 1h
requiredDataConnectors:
- dataTypes:
  - CommonSecurityLog
  connectorId: PaloAltoNetworks
- dataTypes:
  - CommonSecurityLog
  connectorId: PaloAltoNetworksAma
tactics:
- Discovery
{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "workspace": {
      "type": "String"
    }
  },
  "resources": [
    {
      "apiVersion": "2023-02-01-preview",
      "id": "[concat(resourceId('Microsoft.OperationalInsights/workspaces/providers', parameters('workspace'), 'Microsoft.SecurityInsights'),'/alertRules/5b72f527-e3f6-4a00-9908-8e4fee14da9f')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/5b72f527-e3f6-4a00-9908-8e4fee14da9f')]",
      "properties": {
        "alertRuleTemplateName": "5b72f527-e3f6-4a00-9908-8e4fee14da9f",
        "customDetails": null,
        "description": "'Identifies a list of internal Source IPs (10.x.x.x Hosts) that have triggered 10 or more non-graceful tcp server resets from one or more Destination IPs which\nresults in an \"ApplicationProtocol = incomplete\" designation. The server resets coupled with an \"Incomplete\" ApplicationProtocol designation can be an indication\nof internal to external port scanning or probing attack.\nReferences: https://knowledgebase.paloaltonetworks.com/KCSArticleDetail?id=kA10g000000ClUvCAK and\nhttps://knowledgebase.paloaltonetworks.com/KCSArticleDetail?id=kA10g000000ClTaCAK'\n",
        "displayName": "Palo Alto - possible internal to external port scanning",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "AccountCustomEntity",
                "identifier": "FullName"
              }
            ]
          },
          {
            "entityType": "Host",
            "fieldMappings": [
              {
                "columnName": "HostCustomEntity",
                "identifier": "FullName"
              }
            ]
          },
          {
            "entityType": "IP",
            "fieldMappings": [
              {
                "columnName": "IPCustomEntity",
                "identifier": "Address"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/PaloAlto-PAN-OS/Analytic Rules/PaloAlto-PortScanning.yaml",
        "query": "CommonSecurityLog\n| where isnotempty(DestinationPort) and DeviceAction !in (\"reset-both\", \"deny\")\n// filter out common usage ports. Add ports that are legitimate for your environment\n| where DestinationPort !in (\"443\", \"53\", \"389\", \"80\", \"0\", \"880\", \"8888\", \"8080\")\n| where ApplicationProtocol == \"incomplete\"\n// filter out IANA ephemeral or negotiated ports as per https://en.wikipedia.org/wiki/Ephemeral_port\n| where DestinationPort !between (toint(49512) .. toint(65535))\n| where Computer != \"\"\n| where DestinationIP !startswith \"10.\"\n| extend Reason = coalesce(\n                              column_ifexists(\"Reason\", \"\"),\n                              extract(\"reason=(.+?)(;|$)\", 1, AdditionalExtensions),\n                              \"\"\n                          )\n// Filter out any graceful reset reasons of AGED OUT which occurs when a TCP session closes with a FIN due to aging out.\n| where Reason !has \"aged-out\"\n// Filter out any TCP FIN which occurs when a TCP FIN is used to gracefully close half or both sides of a connection.\n| where Reason !has \"tcp-fin\"\n// Uncomment one of the following where clauses to trigger on specific TCP reset reasons\n// See Palo Alto article for details - https://knowledgebase.paloaltonetworks.com/KCSArticleDetail?id=kA10g000000ClUvCAK\n// TCP RST-server - Occurs when the server sends a TCP reset to the client\n// | where AdditionalExtensions has \"reason=tcp-rst-from-server\"\n// TCP RST-client - Occurs when the client sends a TCP reset to the server\n// | where AdditionalExtensions has \"reason=tcp-rst-from-client\"\n// Already performed\n//| extend reason = tostring(split(AdditionalExtensions, \";\")[3])\n| summarize StartTimeUtc = min(TimeGenerated), EndTimeUtc = max(TimeGenerated), count() by DeviceName, SourceUserID, SourceIP, ApplicationProtocol, Reason, DestinationPort, Protocol, DeviceVendor, DeviceProduct, DeviceAction, DestinationIP\n| where count_ >= 10\n| summarize StartTimeUtc = min(StartTimeUtc), EndTimeUtc = max(EndTimeUtc), makeset(DestinationIP), totalcount = sum(count_) by DeviceName, SourceUserID, SourceIP, ApplicationProtocol, Reason, DestinationPort, Protocol, DeviceVendor, DeviceProduct, DeviceAction\n| extend timestamp = StartTimeUtc, IPCustomEntity = SourceIP, AccountCustomEntity = SourceUserID, HostCustomEntity = DeviceName\n",
        "queryFrequency": "PT1H",
        "queryPeriod": "PT1H",
        "severity": "Low",
        "status": "Available",
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "Discovery"
        ],
        "techniques": [
          "T1046"
        ],
        "templateVersion": "1.0.3",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}