Zscaler - Shared ZPA session

let open_sessions =
ZPAEvent
| where DvcAction == 'open'
| summarize timestampstart = min(TimeGenerated) by DstUserName, SrcIpAddr, NetworkSessionId
| sort by timestampstart asc;
let closed_sessions =
ZPAEvent
| where TimeGenerated > ago(1h)
| where DvcAction == 'close'
| summarize timestampend = max(TimeGenerated) by DstUserName, SrcIpAddr, NetworkSessionId
| sort by timestampend asc;
open_sessions
| join (closed_sessions) on DstUserName
| sort by DstUserName, timestampstart
| extend prev_session_closetime = prev(timestampend,1)
| extend prev_session_starttime = prev(timestampstart,1)
| extend PreviousSrcIpAddr = prev(SrcIpAddr, 1)
| extend prev_sessionuser = prev(DstUserName, 1) 
| where DstUserName == prev_sessionuser
| where SrcIpAddr != PreviousSrcIpAddr
| where prev_session_closetime > timestampstart
| project DstUserName, SrcIpAddr, PreviousSrcIpAddr
| extend IPCustomEntity = SrcIpAddr, AccountCustomEntity = DstUserName

severity: High
name: Zscaler - Shared ZPA session
queryPeriod: 24h
id: 40a98355-0e52-479f-8c91-4ab659cba878
requiredDataConnectors:
- connectorId: ZscalerPrivateAccess
  dataTypes:
  - ZPAEvent
kind: Scheduled
tactics:
- InitialAccess
triggerThreshold: 0
description: |
    'Detects shared ZPA session.'
entityMappings:
- fieldMappings:
  - columnName: AccountCustomEntity
    identifier: Name
  entityType: Account
- fieldMappings:
  - columnName: IPCustomEntity
    identifier: Address
  entityType: IP
triggerOperator: gt
queryFrequency: 1h
status: Available
relevantTechniques:
- T1078
- T1133
query: |
  let open_sessions =
  ZPAEvent
  | where DvcAction == 'open'
  | summarize timestampstart = min(TimeGenerated) by DstUserName, SrcIpAddr, NetworkSessionId
  | sort by timestampstart asc;
  let closed_sessions =
  ZPAEvent
  | where TimeGenerated > ago(1h)
  | where DvcAction == 'close'
  | summarize timestampend = max(TimeGenerated) by DstUserName, SrcIpAddr, NetworkSessionId
  | sort by timestampend asc;
  open_sessions
  | join (closed_sessions) on DstUserName
  | sort by DstUserName, timestampstart
  | extend prev_session_closetime = prev(timestampend,1)
  | extend prev_session_starttime = prev(timestampstart,1)
  | extend PreviousSrcIpAddr = prev(SrcIpAddr, 1)
  | extend prev_sessionuser = prev(DstUserName, 1) 
  | where DstUserName == prev_sessionuser
  | where SrcIpAddr != PreviousSrcIpAddr
  | where prev_session_closetime > timestampstart
  | project DstUserName, SrcIpAddr, PreviousSrcIpAddr
  | extend IPCustomEntity = SrcIpAddr, AccountCustomEntity = DstUserName  
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Zscaler Private Access (ZPA)/Analytic Rules/ZscalerSharedZPASession.yaml
version: 1.0.0

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "workspace": {
      "type": "String"
    }
  },
  "resources": [
    {
      "apiVersion": "2023-02-01-preview",
      "id": "[concat(resourceId('Microsoft.OperationalInsights/workspaces/providers', parameters('workspace'), 'Microsoft.SecurityInsights'),'/alertRules/40a98355-0e52-479f-8c91-4ab659cba878')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/40a98355-0e52-479f-8c91-4ab659cba878')]",
      "properties": {
        "alertRuleTemplateName": "40a98355-0e52-479f-8c91-4ab659cba878",
        "customDetails": null,
        "description": "'Detects shared ZPA session.'\n",
        "displayName": "Zscaler - Shared ZPA session",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "AccountCustomEntity",
                "identifier": "Name"
              }
            ]
          },
          {
            "entityType": "IP",
            "fieldMappings": [
              {
                "columnName": "IPCustomEntity",
                "identifier": "Address"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Zscaler Private Access (ZPA)/Analytic Rules/ZscalerSharedZPASession.yaml",
        "query": "let open_sessions =\nZPAEvent\n| where DvcAction == 'open'\n| summarize timestampstart = min(TimeGenerated) by DstUserName, SrcIpAddr, NetworkSessionId\n| sort by timestampstart asc;\nlet closed_sessions =\nZPAEvent\n| where TimeGenerated > ago(1h)\n| where DvcAction == 'close'\n| summarize timestampend = max(TimeGenerated) by DstUserName, SrcIpAddr, NetworkSessionId\n| sort by timestampend asc;\nopen_sessions\n| join (closed_sessions) on DstUserName\n| sort by DstUserName, timestampstart\n| extend prev_session_closetime = prev(timestampend,1)\n| extend prev_session_starttime = prev(timestampstart,1)\n| extend PreviousSrcIpAddr = prev(SrcIpAddr, 1)\n| extend prev_sessionuser = prev(DstUserName, 1) \n| where DstUserName == prev_sessionuser\n| where SrcIpAddr != PreviousSrcIpAddr\n| where prev_session_closetime > timestampstart\n| project DstUserName, SrcIpAddr, PreviousSrcIpAddr\n| extend IPCustomEntity = SrcIpAddr, AccountCustomEntity = DstUserName\n",
        "queryFrequency": "PT1H",
        "queryPeriod": "PT24H",
        "severity": "High",
        "status": "Available",
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "InitialAccess"
        ],
        "techniques": [
          "T1078",
          "T1133"
        ],
        "templateVersion": "1.0.0",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}