Abnormal Port to Protocol

Back


Id	826f930c-2f25-4508-8e75-a95b809a4e15
Rulename	Abnormal Port to Protocol
Description	Identifies communication for well known protocol over a non-standard port based on learning period activity. This can indicate malicious communication (C2) or exfiltration by attackers trying to communicate over known ports (22:SSH, 80:HTTP) but dont use the known protocol headers to match the port number. Configurable Parameters: - Learning period time - learning period for protocol learning in days. Default is set to 7.
Severity	Medium
Tactics	DefenseEvasion Exfiltration CommandAndControl
Required data connectors	AzureFirewall
Kind	Scheduled
Query frequency	1h
Query period	8d
Trigger threshold	1
Trigger operator	gt
Source Uri	https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Azure Firewall/Analytic Rules/Azure Firewall - Abnormal Port to Protocol.yaml
Version	1.1.1
Arm template	826f930c-2f25-4508-8e75-a95b809a4e15.json

KQL

let LearningPeriod = 7d;
let RunTime = 1d;
let StartLearningPeriod = LearningPeriod + RunTime;
let EndRunTime = RunTime - 1d;
let LearningPortToProtocol1 =  (AzureDiagnostics
| where OperationName == "AzureFirewallApplicationRuleLog"
| where TimeGenerated between (ago(StartLearningPeriod) .. ago(RunTime))
| extend msg_s= column_ifexists('msg_s',Message)
| parse msg_s with Protocol " request from " SourceIp ":" SourcePort:int " to " Fqdn ":" DestinationPort:int "." *
| where isnotempty(DestinationPort)
| summarize LearningTimeCount = count() by LearningTimeDstPort = DestinationPort, LearningTimeProtocol = Protocol, SourceIp, Fqdn);
let LearningPortToProtocol2 = (AZFWNetworkRule
| where TimeGenerated between (ago(StartLearningPeriod) .. ago(RunTime))
| where isnotempty(DestinationPort)
| extend Fqdn = DestinationIp
| summarize LearningTimeCount = count() by LearningTimeDstPort = DestinationPort, LearningTimeProtocol = Protocol, SourceIp, Fqdn);
let LearningPortToProtocol3 = (AZFWApplicationRule
| where TimeGenerated between (ago(StartLearningPeriod) .. ago(RunTime))
| where isnotempty(DestinationPort)
| summarize LearningTimeCount = count() by LearningTimeDstPort = DestinationPort, LearningTimeProtocol = Protocol, SourceIp, Fqdn);
let AlertTimePortToProtocol1 = (AzureDiagnostics
| where TimeGenerated between (ago(RunTime) .. ago(EndRunTime))
| where OperationName == "AzureFirewallApplicationRuleLog"
| extend msg_s= column_ifexists('msg_s',Message)
| parse msg_s with Protocol " request from " SourceIp ":" SourcePort " to " Fqdn ":" DestinationPort:int "." *
| where isnotempty(DestinationPort)
| summarize AlertTimeCount = count() by AlertTimeDstPort = DestinationPort, AlertTimeProtocol = Protocol);
let AlertTimePortToProtocol2 = (AZFWNetworkRule
| where TimeGenerated between (ago(RunTime) .. ago(EndRunTime))
| where isnotempty(DestinationPort)
| extend Fqdn = DestinationIp
| summarize AlertTimeCount = count() by AlertTimeDstPort = DestinationPort, AlertTimeProtocol = Protocol);
let AlertTimePortToProtocol3 = (AZFWApplicationRule
| where TimeGenerated between (ago(RunTime) .. ago(EndRunTime))
| where isnotempty(DestinationPort)
| summarize AlertTimeCount = count() by AlertTimeDstPort = DestinationPort, AlertTimeProtocol = Protocol);
(union isfuzzy=true 
(AlertTimePortToProtocol1 
| join kind=leftouter (LearningPortToProtocol1) on $left.AlertTimeDstPort == $right.LearningTimeDstPort
| where LearningTimeProtocol != AlertTimeProtocol),
(AlertTimePortToProtocol2 
| join kind=leftouter (LearningPortToProtocol2) on $left.AlertTimeDstPort == $right.LearningTimeDstPort
| where LearningTimeProtocol != AlertTimeProtocol),
(AlertTimePortToProtocol3 
| join kind=leftouter (LearningPortToProtocol3) on $left.AlertTimeDstPort == $right.LearningTimeDstPort
| where LearningTimeProtocol != AlertTimeProtocol))

YAML

relevantTechniques: []
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Azure Firewall/Analytic Rules/Azure Firewall - Abnormal Port to Protocol.yaml
triggerOperator: gt
kind: Scheduled
entityMappings:
- fieldMappings:
  - columnName: SourceIp
    identifier: Address
  entityType: IP
- fieldMappings:
  - columnName: Fqdn
    identifier: Url
  entityType: URL
requiredDataConnectors:
- dataTypes:
  - AzureDiagnostics
  - AZFWApplicationRule
  - AZFWNetworkRule
  connectorId: AzureFirewall
queryPeriod: 8d
query: |
  let LearningPeriod = 7d;
  let RunTime = 1d;
  let StartLearningPeriod = LearningPeriod + RunTime;
  let EndRunTime = RunTime - 1d;
  let LearningPortToProtocol1 =  (AzureDiagnostics
  | where OperationName == "AzureFirewallApplicationRuleLog"
  | where TimeGenerated between (ago(StartLearningPeriod) .. ago(RunTime))
  | extend msg_s= column_ifexists('msg_s',Message)
  | parse msg_s with Protocol " request from " SourceIp ":" SourcePort:int " to " Fqdn ":" DestinationPort:int "." *
  | where isnotempty(DestinationPort)
  | summarize LearningTimeCount = count() by LearningTimeDstPort = DestinationPort, LearningTimeProtocol = Protocol, SourceIp, Fqdn);
  let LearningPortToProtocol2 = (AZFWNetworkRule
  | where TimeGenerated between (ago(StartLearningPeriod) .. ago(RunTime))
  | where isnotempty(DestinationPort)
  | extend Fqdn = DestinationIp
  | summarize LearningTimeCount = count() by LearningTimeDstPort = DestinationPort, LearningTimeProtocol = Protocol, SourceIp, Fqdn);
  let LearningPortToProtocol3 = (AZFWApplicationRule
  | where TimeGenerated between (ago(StartLearningPeriod) .. ago(RunTime))
  | where isnotempty(DestinationPort)
  | summarize LearningTimeCount = count() by LearningTimeDstPort = DestinationPort, LearningTimeProtocol = Protocol, SourceIp, Fqdn);
  let AlertTimePortToProtocol1 = (AzureDiagnostics
  | where TimeGenerated between (ago(RunTime) .. ago(EndRunTime))
  | where OperationName == "AzureFirewallApplicationRuleLog"
  | extend msg_s= column_ifexists('msg_s',Message)
  | parse msg_s with Protocol " request from " SourceIp ":" SourcePort " to " Fqdn ":" DestinationPort:int "." *
  | where isnotempty(DestinationPort)
  | summarize AlertTimeCount = count() by AlertTimeDstPort = DestinationPort, AlertTimeProtocol = Protocol);
  let AlertTimePortToProtocol2 = (AZFWNetworkRule
  | where TimeGenerated between (ago(RunTime) .. ago(EndRunTime))
  | where isnotempty(DestinationPort)
  | extend Fqdn = DestinationIp
  | summarize AlertTimeCount = count() by AlertTimeDstPort = DestinationPort, AlertTimeProtocol = Protocol);
  let AlertTimePortToProtocol3 = (AZFWApplicationRule
  | where TimeGenerated between (ago(RunTime) .. ago(EndRunTime))
  | where isnotempty(DestinationPort)
  | summarize AlertTimeCount = count() by AlertTimeDstPort = DestinationPort, AlertTimeProtocol = Protocol);
  (union isfuzzy=true 
  (AlertTimePortToProtocol1 
  | join kind=leftouter (LearningPortToProtocol1) on $left.AlertTimeDstPort == $right.LearningTimeDstPort
  | where LearningTimeProtocol != AlertTimeProtocol),
  (AlertTimePortToProtocol2 
  | join kind=leftouter (LearningPortToProtocol2) on $left.AlertTimeDstPort == $right.LearningTimeDstPort
  | where LearningTimeProtocol != AlertTimeProtocol),
  (AlertTimePortToProtocol3 
  | join kind=leftouter (LearningPortToProtocol3) on $left.AlertTimeDstPort == $right.LearningTimeDstPort
  | where LearningTimeProtocol != AlertTimeProtocol))  
version: 1.1.1
description: |
  'Identifies communication for well known protocol over a non-standard port based on learning period activity. This can indicate malicious communication (C2) or exfiltration by attackers trying to communicate over known ports (22:SSH, 80:HTTP) but dont use the known protocol headers to match the port number.

  Configurable Parameters:

  - Learning period time - learning period for protocol learning in days. Default is set to 7.'  
tactics:
- DefenseEvasion
- Exfiltration
- CommandAndControl
severity: Medium
name: Abnormal Port to Protocol
queryFrequency: 1h
triggerThreshold: 1
status: Available
id: 826f930c-2f25-4508-8e75-a95b809a4e15

ARM

{
  "$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/826f930c-2f25-4508-8e75-a95b809a4e15')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/826f930c-2f25-4508-8e75-a95b809a4e15')]",
      "properties": {
        "alertRuleTemplateName": "826f930c-2f25-4508-8e75-a95b809a4e15",
        "customDetails": null,
        "description": "'Identifies communication for well known protocol over a non-standard port based on learning period activity. This can indicate malicious communication (C2) or exfiltration by attackers trying to communicate over known ports (22:SSH, 80:HTTP) but dont use the known protocol headers to match the port number.\n\nConfigurable Parameters:\n\n- Learning period time - learning period for protocol learning in days. Default is set to 7.'\n",
        "displayName": "Abnormal Port to Protocol",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "IP",
            "fieldMappings": [
              {
                "columnName": "SourceIp",
                "identifier": "Address"
              }
            ]
          },
          {
            "entityType": "URL",
            "fieldMappings": [
              {
                "columnName": "Fqdn",
                "identifier": "Url"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Azure Firewall/Analytic Rules/Azure Firewall - Abnormal Port to Protocol.yaml",
        "query": "let LearningPeriod = 7d;\nlet RunTime = 1d;\nlet StartLearningPeriod = LearningPeriod + RunTime;\nlet EndRunTime = RunTime - 1d;\nlet LearningPortToProtocol1 =  (AzureDiagnostics\n| where OperationName == \"AzureFirewallApplicationRuleLog\"\n| where TimeGenerated between (ago(StartLearningPeriod) .. ago(RunTime))\n| extend msg_s= column_ifexists('msg_s',Message)\n| parse msg_s with Protocol \" request from \" SourceIp \":\" SourcePort:int \" to \" Fqdn \":\" DestinationPort:int \".\" *\n| where isnotempty(DestinationPort)\n| summarize LearningTimeCount = count() by LearningTimeDstPort = DestinationPort, LearningTimeProtocol = Protocol, SourceIp, Fqdn);\nlet LearningPortToProtocol2 = (AZFWNetworkRule\n| where TimeGenerated between (ago(StartLearningPeriod) .. ago(RunTime))\n| where isnotempty(DestinationPort)\n| extend Fqdn = DestinationIp\n| summarize LearningTimeCount = count() by LearningTimeDstPort = DestinationPort, LearningTimeProtocol = Protocol, SourceIp, Fqdn);\nlet LearningPortToProtocol3 = (AZFWApplicationRule\n| where TimeGenerated between (ago(StartLearningPeriod) .. ago(RunTime))\n| where isnotempty(DestinationPort)\n| summarize LearningTimeCount = count() by LearningTimeDstPort = DestinationPort, LearningTimeProtocol = Protocol, SourceIp, Fqdn);\nlet AlertTimePortToProtocol1 = (AzureDiagnostics\n| where TimeGenerated between (ago(RunTime) .. ago(EndRunTime))\n| where OperationName == \"AzureFirewallApplicationRuleLog\"\n| extend msg_s= column_ifexists('msg_s',Message)\n| parse msg_s with Protocol \" request from \" SourceIp \":\" SourcePort \" to \" Fqdn \":\" DestinationPort:int \".\" *\n| where isnotempty(DestinationPort)\n| summarize AlertTimeCount = count() by AlertTimeDstPort = DestinationPort, AlertTimeProtocol = Protocol);\nlet AlertTimePortToProtocol2 = (AZFWNetworkRule\n| where TimeGenerated between (ago(RunTime) .. ago(EndRunTime))\n| where isnotempty(DestinationPort)\n| extend Fqdn = DestinationIp\n| summarize AlertTimeCount = count() by AlertTimeDstPort = DestinationPort, AlertTimeProtocol = Protocol);\nlet AlertTimePortToProtocol3 = (AZFWApplicationRule\n| where TimeGenerated between (ago(RunTime) .. ago(EndRunTime))\n| where isnotempty(DestinationPort)\n| summarize AlertTimeCount = count() by AlertTimeDstPort = DestinationPort, AlertTimeProtocol = Protocol);\n(union isfuzzy=true \n(AlertTimePortToProtocol1 \n| join kind=leftouter (LearningPortToProtocol1) on $left.AlertTimeDstPort == $right.LearningTimeDstPort\n| where LearningTimeProtocol != AlertTimeProtocol),\n(AlertTimePortToProtocol2 \n| join kind=leftouter (LearningPortToProtocol2) on $left.AlertTimeDstPort == $right.LearningTimeDstPort\n| where LearningTimeProtocol != AlertTimeProtocol),\n(AlertTimePortToProtocol3 \n| join kind=leftouter (LearningPortToProtocol3) on $left.AlertTimeDstPort == $right.LearningTimeDstPort\n| where LearningTimeProtocol != AlertTimeProtocol))\n",
        "queryFrequency": "PT1H",
        "queryPeriod": "P8D",
        "severity": "Medium",
        "status": "Available",
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "CommandAndControl",
          "DefenseEvasion",
          "Exfiltration"
        ],
        "techniques": [],
        "templateVersion": "1.1.1",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 1
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}