Dataverse - Terminated employee exfiltration to USB drive

let drive_mount_lookback = 14d;
let query_frequency = 1h;
DataverseActivity
| distinct InstanceUrl
| join kind=inner (DeviceFileEvents
    | where TimeGenerated >= ago(query_frequency))
    on $left.InstanceUrl == $right.FileOriginUrl
| join kind=inner (MSBizAppsTerminatedEmployees()) on $left.InitiatingProcessAccountUpn == $right.UserPrincipalName
| join kind=inner (DeviceEvents
    | where TimeGenerated >= ago(drive_mount_lookback)
    | where ActionType == "UsbDriveMounted"
    | extend DriveLetter = tostring(AdditionalFields.DriveLetter)
    | summarize MountedDriveLetters = make_set(DriveLetter, 26) by DeviceId, DeviceName)
    on DeviceId
| extend TargetDriveLetter = tostring(split(FolderPath, "\\")[0])
| where set_has_element(MountedDriveLetters, TargetDriveLetter)
| join kind=inner (DeviceInfo
    | summarize arg_max(TimeGenerated, DeviceId, PublicIP) by DeviceName)
    on DeviceId
| project-rename
    UserId = UserPrincipalName
| summarize LatestEvent = arg_max(TimeGenerated, *), Files = make_set(FileName, 100) by UserId, InstanceUrl
| extend
    CloudAppId = int(32780),
    AccountName = tostring(split(UserId, '@')[0]),
    UPNSuffix = tostring(split(UserId, '@')[1])
| project
    LatestEvent,
    UserId,
    PublicIP,
    Files,
    InstanceUrl,
    CloudAppId,
    AccountName,
    UPNSuffix

queryPeriod: 14d
status: Available
triggerOperator: gt
id: c5e75cb6-cea0-49c2-a998-da414035aac1
version: 3.2.0
alertDetailsOverride:
  alertDisplayNameFormat: Dataverse - terminated user copied files from {{InstanceUrl}} to USB
  alertDescriptionFormat: '{{UserId}} , on the TerminatedUsers watchlist, was found to copy files to a USB mounted drive.'
description: Identifies files downloaded from Dataverse by departing or terminated employees which are copied to USB mounted drives.
customDetails: {}
relevantTechniques:
- T1052
entityMappings:
- entityType: Account
  fieldMappings:
  - identifier: Name
    columnName: AccountName
  - identifier: UPNSuffix
    columnName: UPNSuffix
- entityType: IP
  fieldMappings:
  - identifier: Address
    columnName: PublicIP
- entityType: CloudApplication
  fieldMappings:
  - identifier: AppId
    columnName: CloudAppId
  - identifier: InstanceName
    columnName: InstanceUrl
tactics:
- Exfiltration
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Microsoft%20Business%20Applications/Analytic%20Rules/Dataverse%20-%20Terminated%20employee%20exfiltration%20to%20USB%20drive.yaml
kind: Scheduled
triggerThreshold: 0
severity: High
queryFrequency: 1h
query: |
  let drive_mount_lookback = 14d;
  let query_frequency = 1h;
  DataverseActivity
  | distinct InstanceUrl
  | join kind=inner (DeviceFileEvents
      | where TimeGenerated >= ago(query_frequency))
      on $left.InstanceUrl == $right.FileOriginUrl
  | join kind=inner (MSBizAppsTerminatedEmployees()) on $left.InitiatingProcessAccountUpn == $right.UserPrincipalName
  | join kind=inner (DeviceEvents
      | where TimeGenerated >= ago(drive_mount_lookback)
      | where ActionType == "UsbDriveMounted"
      | extend DriveLetter = tostring(AdditionalFields.DriveLetter)
      | summarize MountedDriveLetters = make_set(DriveLetter, 26) by DeviceId, DeviceName)
      on DeviceId
  | extend TargetDriveLetter = tostring(split(FolderPath, "\\")[0])
  | where set_has_element(MountedDriveLetters, TargetDriveLetter)
  | join kind=inner (DeviceInfo
      | summarize arg_max(TimeGenerated, DeviceId, PublicIP) by DeviceName)
      on DeviceId
  | project-rename
      UserId = UserPrincipalName
  | summarize LatestEvent = arg_max(TimeGenerated, *), Files = make_set(FileName, 100) by UserId, InstanceUrl
  | extend
      CloudAppId = int(32780),
      AccountName = tostring(split(UserId, '@')[0]),
      UPNSuffix = tostring(split(UserId, '@')[1])
  | project
      LatestEvent,
      UserId,
      PublicIP,
      Files,
      InstanceUrl,
      CloudAppId,
      AccountName,
      UPNSuffix
eventGroupingSettings:
  aggregationKind: AlertPerResult
name: Dataverse - Terminated employee exfiltration to USB drive
requiredDataConnectors:
- connectorId: Dataverse
  dataTypes:
  - DataverseActivity
- connectorId: MicrosoftThreatProtection
  dataTypes:
  - DeviceInfo
  - DeviceEvents
  - DeviceFileEvents

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "workspace": {
      "type": "String"
    }
  },
  "resources": [
    {
      "apiVersion": "2024-01-01-preview",
      "id": "[concat(resourceId('Microsoft.OperationalInsights/workspaces/providers', parameters('workspace'), 'Microsoft.SecurityInsights'),'/alertRules/c5e75cb6-cea0-49c2-a998-da414035aac1')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/c5e75cb6-cea0-49c2-a998-da414035aac1')]",
      "properties": {
        "alertDetailsOverride": {
          "alertDescriptionFormat": "{{UserId}} , on the TerminatedUsers watchlist, was found to copy files to a USB mounted drive.",
          "alertDisplayNameFormat": "Dataverse - terminated user copied files from {{InstanceUrl}} to USB"
        },
        "alertRuleTemplateName": "c5e75cb6-cea0-49c2-a998-da414035aac1",
        "customDetails": {},
        "description": "Identifies files downloaded from Dataverse by departing or terminated employees which are copied to USB mounted drives.",
        "displayName": "Dataverse - Terminated employee exfiltration to USB drive",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "AccountName",
                "identifier": "Name"
              },
              {
                "columnName": "UPNSuffix",
                "identifier": "UPNSuffix"
              }
            ]
          },
          {
            "entityType": "IP",
            "fieldMappings": [
              {
                "columnName": "PublicIP",
                "identifier": "Address"
              }
            ]
          },
          {
            "entityType": "CloudApplication",
            "fieldMappings": [
              {
                "columnName": "CloudAppId",
                "identifier": "AppId"
              },
              {
                "columnName": "InstanceUrl",
                "identifier": "InstanceName"
              }
            ]
          }
        ],
        "eventGroupingSettings": {
          "aggregationKind": "AlertPerResult"
        },
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Microsoft%20Business%20Applications/Analytic%20Rules/Dataverse%20-%20Terminated%20employee%20exfiltration%20to%20USB%20drive.yaml",
        "query": "let drive_mount_lookback = 14d;\nlet query_frequency = 1h;\nDataverseActivity\n| distinct InstanceUrl\n| join kind=inner (DeviceFileEvents\n    | where TimeGenerated >= ago(query_frequency))\n    on $left.InstanceUrl == $right.FileOriginUrl\n| join kind=inner (MSBizAppsTerminatedEmployees()) on $left.InitiatingProcessAccountUpn == $right.UserPrincipalName\n| join kind=inner (DeviceEvents\n    | where TimeGenerated >= ago(drive_mount_lookback)\n    | where ActionType == \"UsbDriveMounted\"\n    | extend DriveLetter = tostring(AdditionalFields.DriveLetter)\n    | summarize MountedDriveLetters = make_set(DriveLetter, 26) by DeviceId, DeviceName)\n    on DeviceId\n| extend TargetDriveLetter = tostring(split(FolderPath, \"\\\\\")[0])\n| where set_has_element(MountedDriveLetters, TargetDriveLetter)\n| join kind=inner (DeviceInfo\n    | summarize arg_max(TimeGenerated, DeviceId, PublicIP) by DeviceName)\n    on DeviceId\n| project-rename\n    UserId = UserPrincipalName\n| summarize LatestEvent = arg_max(TimeGenerated, *), Files = make_set(FileName, 100) by UserId, InstanceUrl\n| extend\n    CloudAppId = int(32780),\n    AccountName = tostring(split(UserId, '@')[0]),\n    UPNSuffix = tostring(split(UserId, '@')[1])\n| project\n    LatestEvent,\n    UserId,\n    PublicIP,\n    Files,\n    InstanceUrl,\n    CloudAppId,\n    AccountName,\n    UPNSuffix\n",
        "queryFrequency": "PT1H",
        "queryPeriod": "P14D",
        "severity": "High",
        "status": "Available",
        "subTechniques": [],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "Exfiltration"
        ],
        "techniques": [
          "T1052"
        ],
        "templateVersion": "3.2.0",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}