Netskope - Anomalous User Behavior High Volume from Unmanaged Device

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Id	fa4c4f1c-3c5f-4c3a-a13f-924c30db56e9
Rulename	Netskope - Anomalous User Behavior (High Volume from Unmanaged Device)
Description	Detects anomalous user behavior including high data volume transfers from unmanaged devices, unusual access patterns, and suspicious application usage.
Severity	Medium
Tactics	Exfiltration Collection
Techniques	T1567 T1074
Required data connectors	NetskopeWebTxConnector
Kind	Scheduled
Query frequency	1h
Query period	1h
Trigger threshold	0
Trigger operator	gt
Source Uri	https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/NetskopeWebTx/Analytic Rules/NetskopeWebtx_Rule1.yaml
Version	1.0.0
Arm template	fa4c4f1c-3c5f-4c3a-a13f-924c30db56e9.json

KQL

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

YAML

id: fa4c4f1c-3c5f-4c3a-a13f-924c30db56e9
triggerOperator: gt
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/NetskopeWebTx/Analytic Rules/NetskopeWebtx_Rule1.yaml
entityMappings:
- fieldMappings:
  - identifier: Name
    columnName: User
  entityType: Account
- fieldMappings:
  - identifier: HostName
    columnName: Device
  entityType: Host
requiredDataConnectors:
- dataTypes:
  - NetskopeWebTransactions_CL
  connectorId: NetskopeWebTxConnector
queryFrequency: 1h
queryPeriod: 1h
status: Available
query: |
  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  
name: Netskope - Anomalous User Behavior (High Volume from Unmanaged Device)
kind: Scheduled
tactics:
- Exfiltration
- Collection
severity: Medium
relevantTechniques:
- T1567
- T1074
triggerThreshold: 0
version: 1.0.0
description: |
    Detects anomalous user behavior including high data volume transfers from unmanaged devices, unusual access patterns, and suspicious application usage.

ARM