Netskope - Anomalous User Behavior (High Volume from Unmanaged Device)

Requête originale, sans modification.

let highVolumeThresholdGB = 1;
NetskopeWebTransactions_CL
| where TimeGenerated > ago(1h)
| where isnotempty(CsUsername)
| summarize 
    TotalBytes = sum(Bytes),
    UploadBytes = sum(CsBytes),
    DownloadBytes = sum(ScBytes),
    UniqueApps = dcount(XCsApp),
    Apps = make_set(XCsApp, 20),
    UniqueHosts = dcount(CsHost),
    Activities = make_set(XCsAppActivity),
    Countries = make_set(XCCountry),
    Devices = make_set(XCDevice),
    AccessMethods = make_set(XCsAccessMethod),
    EventCount = count()
    by CsUsername, XCDevice, XCsAccessMethod
| extend 
    TotalGB = round(TotalBytes / 1073741824.0, 3),
    UploadGB = round(UploadBytes / 1073741824.0, 3),
    DownloadGB = round(DownloadBytes / 1073741824.0, 3)
| where TotalGB > highVolumeThresholdGB
| extend IsUnmanagedDevice = XCDevice =~ 'unmanaged' or XCDevice =~ 'BYOD' or XCDevice =~ 'Personal' or XCDevice =~ 'Unknown' or XCsAccessMethod != 'Client'
| where IsUnmanagedDevice or TotalGB > 5 or UniqueApps > 20
| extend RiskIndicators = strcat_array(array_concat(
    iff(IsUnmanagedDevice, dynamic(['Unmanaged Device']), dynamic([])),
    iff(TotalGB > 5, dynamic(['High Data Volume']), dynamic([])),
    iff(UniqueApps > 20, dynamic(['Many Apps Accessed']), dynamic([])),
    iff(array_length(Countries) > 1, dynamic(['Multiple Countries']), dynamic([]))
), ', ')
| project 
    TimeGenerated = now(),
    User = CsUsername,
    Device = XCDevice,
    AccessMethod = XCsAccessMethod,
    TotalDataGB = TotalGB,
    UploadGB,
    DownloadGB,
    UniqueApplications = UniqueApps,
    Applications = Apps,
    UniqueHosts,
    Activities,
    Countries,
    EventCount,
    IsUnmanagedDevice,
    RiskIndicators