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

Detect port misuse by static threshold ASIM Network Session schema

Back
Id156997bd-da0f-4729-b47a-0a3e02dd50c8
RulenameDetect port misuse by static threshold (ASIM Network Session schema)
DescriptionThis detection rule detects port usage above the configured threshold. The rule utilize ASIM normalization, and is applied to any source which supports the ASIM Network Session schema. To tune the rule to your environment configure it using the ‘NetworkSession_Monitor_Configuration’ watchlist. This rule leverages log summaries generated by a Summary Rule or Summarized Playbook. If no such summaries are available, the rule falls back to direct analysis using ASIM function.
SeverityMedium
TacticsCommandAndControl
Execution
InitialAccess
TechniquesT1095
T1059
T1203
T1190
Required data connectorsAIVectraStream
AWSS3
AzureFirewall
AzureMonitor(VMInsights)
AzureNSG
CheckPoint
CiscoASA
CiscoAsaAma
CiscoMeraki
Corelight
Fortinet
MicrosoftSysmonForLinux
MicrosoftThreatProtection
PaloAltoNetworks
SecurityEvents
WindowsForwardedEvents
WindowsSecurityEvents
Zscaler
KindScheduled
Query frequency20m
Query period60m
Trigger threshold0
Trigger operatorgt
Source Urihttps://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Network Session Essentials/Analytic Rules/DetectPortMisuseByStaticThreshold.yaml
Version1.2.0
Arm template156997bd-da0f-4729-b47a-0a3e02dd50c8.json
Deploy To Azure
let lookback = 20m; 
let mapping = _GetWatchlist('NetworkSession_Monitor_Configuration')
    | where Type == "Detection" and ThresholdType == "Static" and Severity != "Disabled"  
    | extend
        Ports = split(Ports, ","),
        App = split(App, ","),
        Protocol = split(Protocol, ","),
        Direction = split(Direction, ","),
        Action = split(Action, ",")
    | project
        Ports,
        App,
        Protocol,
        Direction,
        Action,
        Type,
        ThresholdType,
        Threshold,
        Severity,
        Tactic,
        Name,
        Description
    | mv-expand Ports
    | mv-expand App
    | mv-expand Protocol
    | mv-expand Direction
    | mv-expand Action
    | extend
        Ports = tostring(Ports),
        App = tostring(App),
        Protocol = tostring(Protocol),
        Direction = tostring(Direction),
        Action = tostring(Action),
        Threshold = toint(Threshold);
let NetworkSummary_Protocol = materialize(
    union isfuzzy=true 
        (
        NetworkSummary_Protocol_CL
        | project v = int(2)
        ),
        (
        print int(1) 
        | project v = print_0
        )
    | summarize maxv = max(v)
    | extend
        NetworkSummary_Protocol_Exists = (maxv > 1),
        NetworkCustomAnalyticsExists = false
    );
let NetworkCustomAnalytics = materialize(
    union isfuzzy=true 
        (
        NetworkCustomAnalytics_protocol_CL
        | project v = int(2)
        ),
        (
        print int(1) 
        | project v = print_0
        )
    | summarize maxv = max(v)
    | extend
        NetworkCustomAnalyticsExists = (maxv > 1),
        NetworkSummary_Protocol_Exists = false
    );
let allData = union isfuzzy=true 
        (
        (datatable(
    exists: int,
    NetworkSummary_Protocol_Exists: bool,
    NetworkCustomAnalyticsExists: bool
)[
    1, false, false
]
        | join (NetworkSummary_Protocol) on NetworkSummary_Protocol_Exists
        | join (NetworkCustomAnalytics) on NetworkCustomAnalyticsExists
        )
        | join (
            _Im_NetworkSession(starttime=bin(now(-20m), 20m), endtime=bin(now(), 20m))
            | where TimeGenerated > bin(now(-20m), 20m)
            | summarize Count=count()
                by
                NetworkProtocol,
                DstPortNumber,
                DstAppName,
                NetworkDirection,
                DvcAction,
                bin(TimeGenerated, 20m)
            | extend
                EventTime = TimeGenerated,
                Count = toint(Count),
                DstPortNumber = toint(DstPortNumber),
                exists=int(1)
            )
            on exists
        | project-away exists*, maxv, NetworkSummary_Protocol_Exists*, NetworkCustomAnalyticsExists*
        ),
        (
        (datatable(exists: int, NetworkSummary_Protocol_Exists: bool)[1, false]
        | join (NetworkSummary_Protocol) on NetworkSummary_Protocol_Exists
        )
        | join (
            NetworkCustomAnalytics_protocol_CL
            | where EventTime_t == toscalar(NetworkCustomAnalytics_protocol_CL
                | summarize max(EventTime_t))
            | project
                NetworkProtocol=NetworkProtocol_s,
                DstPortNumber=DstPortNumber_d,
                DstAppName=DstAppName_s,
                NetworkDirection=NetworkDirection_s,
                DvcAction=DvcAction_s,
                Count=count__d,
                EventTime=EventTime_t,
                TimeGenerated,
                Type
            | extend Count = toint(Count), DstPortNumber = toint(DstPortNumber), exists=int(1)
            )
            on exists
        | project-away exists*, maxv, NetworkSummary_Protocol_Exists*, NetworkCustomAnalyticsExists*
        ),
        (
        NetworkSummary_Protocol_CL
        | where EventTime == toscalar(NetworkSummary_Protocol_CL
            | summarize max(EventTime))
        | project
            NetworkProtocol,
            DstPortNumber,
            DstAppName,
            NetworkDirection,
            DvcAction,
            Count=count_,
            EventTime,
            TimeGenerated,
            Type
        | extend Count = toint(Count), DstPortNumber = toint(DstPortNumber)
        )
    | project-away exists*, maxv*, NetworkSummary_Protocol_Exists*, NetworkCustomAnalyticsExists*
;
allData
| where isnotempty(DstPortNumber)
| summarize Sum=sum(Count) by DstPortNumber, NetworkProtocol, NetworkDirection, DvcAction 
| join kind=inner ['mapping'] where Ports has tostring(DstPortNumber)
| where Sum > Threshold         
    and (Protocol == "*" or Protocol has NetworkProtocol)
    and (Direction == "*" or Direction has NetworkDirection)
    and (Action == "*" or Action has DvcAction)
| project
    Name,
    Description,
    NetworkProtocol,
    DstPortNumber,
    NetworkDirection,
    DvcAction,
    Severity,
    Tactic
| summarize
    NetworkProtocols=make_set_if(NetworkProtocol, isnotempty(NetworkProtocol), 20), 
    NetworkDirections=make_set_if(NetworkDirection, isnotempty(NetworkDirection), 5), 
    DvcActions=make_set_if(DvcAction, isnotempty(DvcAction), 10)
    by Name, Severity, Tactic, DstPortNumber, Description
query: |
  let lookback = 20m; 
  let mapping = _GetWatchlist('NetworkSession_Monitor_Configuration')
      | where Type == "Detection" and ThresholdType == "Static" and Severity != "Disabled"  
      | extend
          Ports = split(Ports, ","),
          App = split(App, ","),
          Protocol = split(Protocol, ","),
          Direction = split(Direction, ","),
          Action = split(Action, ",")
      | project
          Ports,
          App,
          Protocol,
          Direction,
          Action,
          Type,
          ThresholdType,
          Threshold,
          Severity,
          Tactic,
          Name,
          Description
      | mv-expand Ports
      | mv-expand App
      | mv-expand Protocol
      | mv-expand Direction
      | mv-expand Action
      | extend
          Ports = tostring(Ports),
          App = tostring(App),
          Protocol = tostring(Protocol),
          Direction = tostring(Direction),
          Action = tostring(Action),
          Threshold = toint(Threshold);
  let NetworkSummary_Protocol = materialize(
      union isfuzzy=true 
          (
          NetworkSummary_Protocol_CL
          | project v = int(2)
          ),
          (
          print int(1) 
          | project v = print_0
          )
      | summarize maxv = max(v)
      | extend
          NetworkSummary_Protocol_Exists = (maxv > 1),
          NetworkCustomAnalyticsExists = false
      );
  let NetworkCustomAnalytics = materialize(
      union isfuzzy=true 
          (
          NetworkCustomAnalytics_protocol_CL
          | project v = int(2)
          ),
          (
          print int(1) 
          | project v = print_0
          )
      | summarize maxv = max(v)
      | extend
          NetworkCustomAnalyticsExists = (maxv > 1),
          NetworkSummary_Protocol_Exists = false
      );
  let allData = union isfuzzy=true 
          (
          (datatable(
      exists: int,
      NetworkSummary_Protocol_Exists: bool,
      NetworkCustomAnalyticsExists: bool
  )[
      1, false, false
  ]
          | join (NetworkSummary_Protocol) on NetworkSummary_Protocol_Exists
          | join (NetworkCustomAnalytics) on NetworkCustomAnalyticsExists
          )
          | join (
              _Im_NetworkSession(starttime=bin(now(-20m), 20m), endtime=bin(now(), 20m))
              | where TimeGenerated > bin(now(-20m), 20m)
              | summarize Count=count()
                  by
                  NetworkProtocol,
                  DstPortNumber,
                  DstAppName,
                  NetworkDirection,
                  DvcAction,
                  bin(TimeGenerated, 20m)
              | extend
                  EventTime = TimeGenerated,
                  Count = toint(Count),
                  DstPortNumber = toint(DstPortNumber),
                  exists=int(1)
              )
              on exists
          | project-away exists*, maxv, NetworkSummary_Protocol_Exists*, NetworkCustomAnalyticsExists*
          ),
          (
          (datatable(exists: int, NetworkSummary_Protocol_Exists: bool)[1, false]
          | join (NetworkSummary_Protocol) on NetworkSummary_Protocol_Exists
          )
          | join (
              NetworkCustomAnalytics_protocol_CL
              | where EventTime_t == toscalar(NetworkCustomAnalytics_protocol_CL
                  | summarize max(EventTime_t))
              | project
                  NetworkProtocol=NetworkProtocol_s,
                  DstPortNumber=DstPortNumber_d,
                  DstAppName=DstAppName_s,
                  NetworkDirection=NetworkDirection_s,
                  DvcAction=DvcAction_s,
                  Count=count__d,
                  EventTime=EventTime_t,
                  TimeGenerated,
                  Type
              | extend Count = toint(Count), DstPortNumber = toint(DstPortNumber), exists=int(1)
              )
              on exists
          | project-away exists*, maxv, NetworkSummary_Protocol_Exists*, NetworkCustomAnalyticsExists*
          ),
          (
          NetworkSummary_Protocol_CL
          | where EventTime == toscalar(NetworkSummary_Protocol_CL
              | summarize max(EventTime))
          | project
              NetworkProtocol,
              DstPortNumber,
              DstAppName,
              NetworkDirection,
              DvcAction,
              Count=count_,
              EventTime,
              TimeGenerated,
              Type
          | extend Count = toint(Count), DstPortNumber = toint(DstPortNumber)
          )
      | project-away exists*, maxv*, NetworkSummary_Protocol_Exists*, NetworkCustomAnalyticsExists*
  ;
  allData
  | where isnotempty(DstPortNumber)
  | summarize Sum=sum(Count) by DstPortNumber, NetworkProtocol, NetworkDirection, DvcAction 
  | join kind=inner ['mapping'] where Ports has tostring(DstPortNumber)
  | where Sum > Threshold         
      and (Protocol == "*" or Protocol has NetworkProtocol)
      and (Direction == "*" or Direction has NetworkDirection)
      and (Action == "*" or Action has DvcAction)
  | project
      Name,
      Description,
      NetworkProtocol,
      DstPortNumber,
      NetworkDirection,
      DvcAction,
      Severity,
      Tactic
  | summarize
      NetworkProtocols=make_set_if(NetworkProtocol, isnotempty(NetworkProtocol), 20), 
      NetworkDirections=make_set_if(NetworkDirection, isnotempty(NetworkDirection), 5), 
      DvcActions=make_set_if(DvcAction, isnotempty(DvcAction), 10)
      by Name, Severity, Tactic, DstPortNumber, Description  
alertDetailsOverride:
  alertDisplayNameFormat: Detected {{Name}}
  alertSeverityColumnName: Severity
  alertDescriptionFormat: '{{Description}}'
  alertTacticsColumnName: Tactic
triggerOperator: gt
eventGroupingSettings:
  aggregationKind: AlertPerResult
description: |
    'This detection rule detects port usage above the configured threshold. The rule utilize [ASIM](https://aka.ms/AboutASIM) normalization, and is applied to any source which supports the ASIM Network Session schema. To tune the rule to your environment configure it using the 'NetworkSession_Monitor_Configuration' watchlist. This rule leverages log summaries generated by a Summary Rule or Summarized Playbook. If no such summaries are available, the rule falls back to direct analysis using ASIM function.'
tactics:
- CommandAndControl
- Execution
- InitialAccess
severity: Medium
queryFrequency: 20m
kind: Scheduled
name: Detect port misuse by static threshold (ASIM Network Session schema)
triggerThreshold: 0
status: Available
customDetails:
  AllNetworkProtocols: NetworkProtocols
  DstPortNumber: DstPortNumber
  AllDvcAction: DvcActions
  AllNetworkDirections: NetworkDirections
id: 156997bd-da0f-4729-b47a-0a3e02dd50c8
version: 1.2.0
requiredDataConnectors:
- connectorId: AWSS3
  dataTypes:
  - AWSVPCFlow
- connectorId: MicrosoftThreatProtection
  dataTypes:
  - DeviceNetworkEvents
- connectorId: SecurityEvents
  dataTypes:
  - SecurityEvent
- connectorId: WindowsSecurityEvents
  dataTypes:
  - SecurityEvent
- connectorId: WindowsForwardedEvents
  dataTypes:
  - WindowsEvent
- connectorId: Zscaler
  dataTypes:
  - CommonSecurityLog
- connectorId: MicrosoftSysmonForLinux
  dataTypes:
  - Syslog
- connectorId: PaloAltoNetworks
  dataTypes:
  - CommonSecurityLog
- connectorId: AzureMonitor(VMInsights)
  dataTypes:
  - VMConnection
- connectorId: AzureFirewall
  dataTypes:
  - AzureDiagnostics
- connectorId: AzureNSG
  dataTypes:
  - AzureDiagnostics
- connectorId: CiscoASA
  dataTypes:
  - CommonSecurityLog
- connectorId: CiscoAsaAma
  dataTypes:
  - CommonSecurityLog
- connectorId: Corelight
  dataTypes:
  - Corelight_CL
- connectorId: AIVectraStream
  dataTypes:
  - VectraStream
- connectorId: CheckPoint
  dataTypes:
  - CommonSecurityLog
- connectorId: Fortinet
  dataTypes:
  - CommonSecurityLog
- connectorId: CiscoMeraki
  dataTypes:
  - Syslog
  - CiscoMerakiNativePoller
relevantTechniques:
- T1095
- T1059
- T1203
- T1190
tags:
- Schema: ASimNetworkSessions
  SchemaVersion: 0.2.4
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Network Session Essentials/Analytic Rules/DetectPortMisuseByStaticThreshold.yaml
queryPeriod: 60m