Vaikora - Quarantine rate spike

let baseline = VaikoraO365_Quarantine_CL
  | where TimeGenerated between (ago(7d) .. ago(1h))
  | summarize HourlyCount = count() by bin(TimeGenerated, 1h), TenantId_s
  | summarize AvgHourlyCount = avg(HourlyCount) by TenantId_s;
VaikoraO365_Quarantine_CL
| where TimeGenerated >= ago(1h)
| summarize RecentCount = count() by TenantId_s
| join kind=inner baseline on TenantId_s
| where RecentCount > (AvgHourlyCount * 3.0)
| where RecentCount >= 10
| project TimeGenerated = now(), TenantId = TenantId_s, RecentCount, AvgHourlyCount, RatioOverBaseline = (RecentCount / AvgHourlyCount)

entityMappings:
- entityType: CloudApplication
  fieldMappings:
  - identifier: Name
    columnName: TenantId
name: Vaikora - Quarantine rate spike
kind: Scheduled
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Vaikora-O365/Analytic%20Rules/Vaikora%20-%20Quarantine%20rate%20spike.yaml
triggerOperator: gt
status: Available
queryPeriod: 7d
requiredDataConnectors:
- connectorId: VaikoraO365
  dataTypes:
  - VaikoraO365_Quarantine_CL
tactics:
- InitialAccess
query: |
  let baseline = VaikoraO365_Quarantine_CL
    | where TimeGenerated between (ago(7d) .. ago(1h))
    | summarize HourlyCount = count() by bin(TimeGenerated, 1h), TenantId_s
    | summarize AvgHourlyCount = avg(HourlyCount) by TenantId_s;
  VaikoraO365_Quarantine_CL
  | where TimeGenerated >= ago(1h)
  | summarize RecentCount = count() by TenantId_s
  | join kind=inner baseline on TenantId_s
  | where RecentCount > (AvgHourlyCount * 3.0)
  | where RecentCount >= 10
  | project TimeGenerated = now(), TenantId = TenantId_s, RecentCount, AvgHourlyCount, RatioOverBaseline = (RecentCount / AvgHourlyCount)
description: |
  Identifies an abnormal spike in Vaikora for O365 quarantine volume for a tenant. Fires when the hourly count exceeds three times the rolling 7-day baseline, signaling a targeted campaign or model surge worth admin review.
severity: Medium
id: 3b3eb1cd-578d-4198-9b7a-bd7253b0dc9f
triggerThreshold: 0
queryFrequency: 1h
alertDetailsOverride:
  alertDescriptionFormat: Quarantine count for the last hour is {{RecentCount}}, which is more than three times the 7-day baseline of {{AvgHourlyCount}}.
  alertDisplayNameFormat: Vaikora-O365 quarantine spike on tenant {{TenantId}}
version: 1.0.0
relevantTechniques:
- T1566

{
  "$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/3b3eb1cd-578d-4198-9b7a-bd7253b0dc9f')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/3b3eb1cd-578d-4198-9b7a-bd7253b0dc9f')]",
      "properties": {
        "alertDetailsOverride": {
          "alertDescriptionFormat": "Quarantine count for the last hour is {{RecentCount}}, which is more than three times the 7-day baseline of {{AvgHourlyCount}}.",
          "alertDisplayNameFormat": "Vaikora-O365 quarantine spike on tenant {{TenantId}}"
        },
        "alertRuleTemplateName": "3b3eb1cd-578d-4198-9b7a-bd7253b0dc9f",
        "customDetails": null,
        "description": "Identifies an abnormal spike in Vaikora for O365 quarantine volume for a tenant. Fires when the hourly count exceeds three times the rolling 7-day baseline, signaling a targeted campaign or model surge worth admin review.\n",
        "displayName": "Vaikora - Quarantine rate spike",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "CloudApplication",
            "fieldMappings": [
              {
                "columnName": "TenantId",
                "identifier": "Name"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Vaikora-O365/Analytic%20Rules/Vaikora%20-%20Quarantine%20rate%20spike.yaml",
        "query": "let baseline = VaikoraO365_Quarantine_CL\n  | where TimeGenerated between (ago(7d) .. ago(1h))\n  | summarize HourlyCount = count() by bin(TimeGenerated, 1h), TenantId_s\n  | summarize AvgHourlyCount = avg(HourlyCount) by TenantId_s;\nVaikoraO365_Quarantine_CL\n| where TimeGenerated >= ago(1h)\n| summarize RecentCount = count() by TenantId_s\n| join kind=inner baseline on TenantId_s\n| where RecentCount > (AvgHourlyCount * 3.0)\n| where RecentCount >= 10\n| project TimeGenerated = now(), TenantId = TenantId_s, RecentCount, AvgHourlyCount, RatioOverBaseline = (RecentCount / AvgHourlyCount)\n",
        "queryFrequency": "PT1H",
        "queryPeriod": "P7D",
        "severity": "Medium",
        "status": "Available",
        "subTechniques": [],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "InitialAccess"
        ],
        "techniques": [
          "T1566"
        ],
        "templateVersion": "1.0.0",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}