Abnormal Port to Protocol
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 | 1h |
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 | 1.0.0 |
Arm template | 826f930c-2f25-4508-8e75-a95b809a4e15.json |
let LearningPeriod = 7d;
let RunTime = 1d;
let StartLearningPeriod = LearningPeriod + RunTime;
let EndRunTime = RunTime - 1d;
let LearningPortToProtocol = (AzureDiagnostics
| where OperationName == "AzureFirewallApplicationRuleLog"
| parse msg_s with protocol " request from " srcip ":" srcport " to " dsturl ":" dstport "." *
| where isnotempty(dstport)
| where TimeGenerated between (ago(StartLearningPeriod) .. ago(RunTime))
| summarize LearningTimeCount = count() by LearningTimeDstPort = dstport, LearningTimeProtocol = protocol, srcip, dsturl);
let AlertTimePortToProtocol = (AzureDiagnostics
| where OperationName == "AzureFirewallApplicationRuleLog"
| parse msg_s with protocol " request from " srcip ":" srcport " to " dsturl ":" dstport "." *
| where isnotempty(dstport)
| where TimeGenerated between (ago(RunTime) .. ago(EndRunTime))
| summarize AlertTimeCount = count() by AlertTimeDstPort = dstport, AlertTimeProtocol = protocol);
AlertTimePortToProtocol
| join kind=leftouter (LearningPortToProtocol) on $left.AlertTimeDstPort == $right.LearningTimeDstPort
| where LearningTimeProtocol != AlertTimeProtocol
| extend IPCustomEntity = srcip, URLCustomEntity = dsturl
severity: Medium
triggerThreshold: 1
query: |
let LearningPeriod = 7d;
let RunTime = 1d;
let StartLearningPeriod = LearningPeriod + RunTime;
let EndRunTime = RunTime - 1d;
let LearningPortToProtocol = (AzureDiagnostics
| where OperationName == "AzureFirewallApplicationRuleLog"
| parse msg_s with protocol " request from " srcip ":" srcport " to " dsturl ":" dstport "." *
| where isnotempty(dstport)
| where TimeGenerated between (ago(StartLearningPeriod) .. ago(RunTime))
| summarize LearningTimeCount = count() by LearningTimeDstPort = dstport, LearningTimeProtocol = protocol, srcip, dsturl);
let AlertTimePortToProtocol = (AzureDiagnostics
| where OperationName == "AzureFirewallApplicationRuleLog"
| parse msg_s with protocol " request from " srcip ":" srcport " to " dsturl ":" dstport "." *
| where isnotempty(dstport)
| where TimeGenerated between (ago(RunTime) .. ago(EndRunTime))
| summarize AlertTimeCount = count() by AlertTimeDstPort = dstport, AlertTimeProtocol = protocol);
AlertTimePortToProtocol
| join kind=leftouter (LearningPortToProtocol) on $left.AlertTimeDstPort == $right.LearningTimeDstPort
| where LearningTimeProtocol != AlertTimeProtocol
| extend IPCustomEntity = srcip, URLCustomEntity = dsturl
queryFrequency: 1h
requiredDataConnectors:
- connectorId: AzureFirewall
dataTypes:
- AzureDiagnostics
id: 826f930c-2f25-4508-8e75-a95b809a4e15
version: 1.0.0
name: Abnormal Port to Protocol
kind: Scheduled
status: Available
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Azure Firewall/Analytic Rules/Azure Firewall - Abnormal Port to Protocol.yaml
queryPeriod: 1h
relevantTechniques: []
triggerOperator: gt
tactics:
- DefenseEvasion
- Exfiltration
- CommandAndControl
description: |
'Identifies communication for well known protocol over a non-standard port based on learning period activity. This can indicate malicious communication (C2) or exfiltration by attackers trying to communicate over known ports (22:SSH, 80:HTTP) but dont use the known protocol headers to match the port number.
Configurable Parameters:
- Learning period time - learning period for protocol learning in days. Default is set to 7.'
entityMappings:
- entityType: IP
fieldMappings:
- identifier: Address
columnName: IPCustomEntity
- entityType: URL
fieldMappings:
- identifier: Url
columnName: URLCustomEntity
{
"$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
"contentVersion": "1.0.0.0",
"parameters": {
"workspace": {
"type": "String"
}
},
"resources": [
{
"id": "[concat(resourceId('Microsoft.OperationalInsights/workspaces/providers', parameters('workspace'), 'Microsoft.SecurityInsights'),'/alertRules/826f930c-2f25-4508-8e75-a95b809a4e15')]",
"name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/826f930c-2f25-4508-8e75-a95b809a4e15')]",
"type": "Microsoft.OperationalInsights/workspaces/providers/alertRules",
"kind": "Scheduled",
"apiVersion": "2022-11-01",
"properties": {
"displayName": "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.\n\nConfigurable Parameters:\n\n- Learning period time - learning period for protocol learning in days. Default is set to 7.'\n",
"severity": "Medium",
"enabled": true,
"query": "let LearningPeriod = 7d;\nlet RunTime = 1d;\nlet StartLearningPeriod = LearningPeriod + RunTime;\nlet EndRunTime = RunTime - 1d;\nlet LearningPortToProtocol = (AzureDiagnostics\n| where OperationName == \"AzureFirewallApplicationRuleLog\"\n| parse msg_s with protocol \" request from \" srcip \":\" srcport \" to \" dsturl \":\" dstport \".\" *\n| where isnotempty(dstport)\n| where TimeGenerated between (ago(StartLearningPeriod) .. ago(RunTime))\n| summarize LearningTimeCount = count() by LearningTimeDstPort = dstport, LearningTimeProtocol = protocol, srcip, dsturl);\nlet AlertTimePortToProtocol = (AzureDiagnostics\n| where OperationName == \"AzureFirewallApplicationRuleLog\"\n| parse msg_s with protocol \" request from \" srcip \":\" srcport \" to \" dsturl \":\" dstport \".\" *\n| where isnotempty(dstport)\n| where TimeGenerated between (ago(RunTime) .. ago(EndRunTime))\n| summarize AlertTimeCount = count() by AlertTimeDstPort = dstport, AlertTimeProtocol = protocol);\nAlertTimePortToProtocol \n| join kind=leftouter (LearningPortToProtocol) on $left.AlertTimeDstPort == $right.LearningTimeDstPort\n| where LearningTimeProtocol != AlertTimeProtocol\n| extend IPCustomEntity = srcip, URLCustomEntity = dsturl\n",
"queryFrequency": "PT1H",
"queryPeriod": "PT1H",
"triggerOperator": "GreaterThan",
"triggerThreshold": 1,
"suppressionDuration": "PT1H",
"suppressionEnabled": false,
"tactics": [
"DefenseEvasion",
"Exfiltration",
"CommandAndControl"
],
"techniques": [],
"alertRuleTemplateName": "826f930c-2f25-4508-8e75-a95b809a4e15",
"customDetails": null,
"entityMappings": [
{
"fieldMappings": [
{
"columnName": "IPCustomEntity",
"identifier": "Address"
}
],
"entityType": "IP"
},
{
"fieldMappings": [
{
"columnName": "URLCustomEntity",
"identifier": "Url"
}
],
"entityType": "URL"
}
],
"OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Azure Firewall/Analytic Rules/Azure Firewall - Abnormal Port to Protocol.yaml",
"templateVersion": "1.0.0",
"status": "Available"
}
}
]
}