User joining Zoom meeting from suspicious timezone

let schedule_lookback = 14d;
let join_lookback = 1d;
// If you want to whitelist specific timezones include them in a list here
let tz_whitelist = dynamic([]);
let meetings = (
ZoomLogs
| where TimeGenerated >= ago(schedule_lookback)
| where Event =~ "meeting.created"
| extend MeetingId = tostring(parse_json(MeetingEvents).MeetingId)
| extend SchedTimezone = tostring(parse_json(MeetingEvents).Timezone));
ZoomLogs
| where TimeGenerated >= ago(join_lookback)
| where Event =~ "meeting.participant_joined"
| extend JoinedTimeZone = tostring(parse_json(MeetingEvents).Timezone)
| extend MeetingName = tostring(parse_json(MeetingEvents).MeetingName)
| extend MeetingId = tostring(parse_json(MeetingEvents).MeetingId)
| where JoinedTimeZone !in (tz_whitelist)
| join (meetings) on MeetingId
| where SchedTimezone != JoinedTimeZone
| project TimeGenerated, MeetingName, JoiningUser=payload_object_participant_user_name_s, JoinedTimeZone, SchedTimezone, MeetingScheduler=User1
| extend AccountName = tostring(split(JoiningUser, "@")[0]), AccountUPNSuffix = tostring(split(JoiningUser, "@")[1])

kind: Scheduled
id: 58fc0170-0877-4ea8-a9ff-d805e361cfae
entityMappings:
- fieldMappings:
  - identifier: FullName
    columnName: JoiningUser
  - identifier: Name
    columnName: AccountName
  - identifier: UPNSuffix
    columnName: AccountUPNSuffix
  entityType: Account
name: User joining Zoom meeting from suspicious timezone
severity: Low
triggerOperator: gt
tactics:
- InitialAccess
- PrivilegeEscalation
query: |
  let schedule_lookback = 14d;
  let join_lookback = 1d;
  // If you want to whitelist specific timezones include them in a list here
  let tz_whitelist = dynamic([]);
  let meetings = (
  ZoomLogs
  | where TimeGenerated >= ago(schedule_lookback)
  | where Event =~ "meeting.created"
  | extend MeetingId = tostring(parse_json(MeetingEvents).MeetingId)
  | extend SchedTimezone = tostring(parse_json(MeetingEvents).Timezone));
  ZoomLogs
  | where TimeGenerated >= ago(join_lookback)
  | where Event =~ "meeting.participant_joined"
  | extend JoinedTimeZone = tostring(parse_json(MeetingEvents).Timezone)
  | extend MeetingName = tostring(parse_json(MeetingEvents).MeetingName)
  | extend MeetingId = tostring(parse_json(MeetingEvents).MeetingId)
  | where JoinedTimeZone !in (tz_whitelist)
  | join (meetings) on MeetingId
  | where SchedTimezone != JoinedTimeZone
  | project TimeGenerated, MeetingName, JoiningUser=payload_object_participant_user_name_s, JoinedTimeZone, SchedTimezone, MeetingScheduler=User1
  | extend AccountName = tostring(split(JoiningUser, "@")[0]), AccountUPNSuffix = tostring(split(JoiningUser, "@")[1])  
triggerThreshold: 0
description: |
  'The alert shows users that join a Zoom meeting from a time zone other than the one the meeting was created in.
  You can also whitelist known good time zones in the tz_whitelist value using the tz database name format https://en.wikipedia.org/wiki/List_of_tz_database_time_zones'  
metadata:
  categories:
    domains:
    - Security - Others
  support:
    tier: Community
  source:
    kind: Community
  author:
    name: Microsoft Security Research
queryFrequency: 1d
queryPeriod: 14d
relevantTechniques:
- T1078
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Detections/ZoomLogs/JoiningMeetingFromAnotherTimeZone.yaml
requiredDataConnectors: []
version: 1.0.4

{
  "$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/58fc0170-0877-4ea8-a9ff-d805e361cfae')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/58fc0170-0877-4ea8-a9ff-d805e361cfae')]",
      "properties": {
        "alertRuleTemplateName": "58fc0170-0877-4ea8-a9ff-d805e361cfae",
        "customDetails": null,
        "description": "'The alert shows users that join a Zoom meeting from a time zone other than the one the meeting was created in.\nYou can also whitelist known good time zones in the tz_whitelist value using the tz database name format https://en.wikipedia.org/wiki/List_of_tz_database_time_zones'\n",
        "displayName": "User joining Zoom meeting from suspicious timezone",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "JoiningUser",
                "identifier": "FullName"
              },
              {
                "columnName": "AccountName",
                "identifier": "Name"
              },
              {
                "columnName": "AccountUPNSuffix",
                "identifier": "UPNSuffix"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Detections/ZoomLogs/JoiningMeetingFromAnotherTimeZone.yaml",
        "query": "let schedule_lookback = 14d;\nlet join_lookback = 1d;\n// If you want to whitelist specific timezones include them in a list here\nlet tz_whitelist = dynamic([]);\nlet meetings = (\nZoomLogs\n| where TimeGenerated >= ago(schedule_lookback)\n| where Event =~ \"meeting.created\"\n| extend MeetingId = tostring(parse_json(MeetingEvents).MeetingId)\n| extend SchedTimezone = tostring(parse_json(MeetingEvents).Timezone));\nZoomLogs\n| where TimeGenerated >= ago(join_lookback)\n| where Event =~ \"meeting.participant_joined\"\n| extend JoinedTimeZone = tostring(parse_json(MeetingEvents).Timezone)\n| extend MeetingName = tostring(parse_json(MeetingEvents).MeetingName)\n| extend MeetingId = tostring(parse_json(MeetingEvents).MeetingId)\n| where JoinedTimeZone !in (tz_whitelist)\n| join (meetings) on MeetingId\n| where SchedTimezone != JoinedTimeZone\n| project TimeGenerated, MeetingName, JoiningUser=payload_object_participant_user_name_s, JoinedTimeZone, SchedTimezone, MeetingScheduler=User1\n| extend AccountName = tostring(split(JoiningUser, \"@\")[0]), AccountUPNSuffix = tostring(split(JoiningUser, \"@\")[1])\n",
        "queryFrequency": "P1D",
        "queryPeriod": "P14D",
        "severity": "Low",
        "subTechniques": [],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "InitialAccess",
          "PrivilegeEscalation"
        ],
        "techniques": [
          "T1078"
        ],
        "templateVersion": "1.0.4",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}