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Detect port misuse by static threshold (ASIM Network Session schema)

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.'
Type de règle
Scheduled
Version
1.2.0
Statut déclaré
Available
Fréquence
20m
Période analysée
60m
Déclenchement
gt 0

Couverture MITRE déclarée

Sources déclarées

Métadonnées du fichier source. Aucune dépendance déduite du KQL.

Connecteurs

Types de données

Requête KQL

Requête originale, sans modification.

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

Contenus associés

Liens établis à partir des identifiants déclarés et des manifests des solutions.

Traçabilité de la source

GitHub

Les valeurs affichées proviennent des fichiers du dépôt Azure/Azure-Sentinel. Elles décrivent le modèle publié, pas la configuration de votre workspace.

Identifiant source
156997bd-da0f-4729-b47a-0a3e02dd50c8
Autres fichiers source 2Solutions/Network Session Essentials/Analytic Rules/DetectPortMisuseByStaticThreshold.yamlsource ↗Solutions/Network Session Essentials/Data/Solution_NetworkSessionEssentials.jsonsolution-membership ↗
GSTEP / SUIVI DU CATALOGUE

Ajouté au catalogue : 16 sept. 2026 · 05:49 UTC
Dernier changement observé : 16 sept. 2026 · 05:49 UTC

Dates de synchronisation GSTEP, distinctes des dates de publication du contenu source.