OracleDBAudit - User activity after long inactivity time

let lbtime_14d = 14d;
let lbtime_7d = 7d;
let lbtime_24h = 24h;
let known_users_14d = OracleDatabaseAuditEvent
| where TimeGenerated between (ago(lbtime_14d) .. ago(lbtime_14d))
| where isnotempty(DstUserName)
| where isnotempty(Action)
| summarize makeset(DstUserName);
let known_users_7d = OracleDatabaseAuditEvent
| where TimeGenerated between (ago(lbtime_7d) .. ago(lbtime_24h))
| where isnotempty(DstUserName)
| where isnotempty(Action)
| summarize makeset(DstUserName);
OracleDatabaseAuditEvent
| where isnotempty(DstUserName)
| where isnotempty(Action)
| where DstUserName !in (known_users_7d)
| where DstUserName in (known_users_14d)
| project DstUserName
| extend AccountCustomEntity = DstUserName

relevantTechniques:
- T1078
name: OracleDBAudit - User activity after long inactivity time
requiredDataConnectors:
- dataTypes:
  - Syslog
  connectorId: OracleDatabaseAudit
- datatypes:
  - Syslog
  connectorId: SyslogAma
entityMappings:
- fieldMappings:
  - identifier: FullName
    columnName: AccountCustomEntity
  entityType: Account
triggerThreshold: 0
id: 5e93a535-036b-4570-9e58-d8992f30e1ae
tactics:
- InitialAccess
- Persistence
version: 1.0.1
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/OracleDatabaseAudit/Analytic Rules/OracleDBAuditRareUserActivity.yaml
queryPeriod: 14d
kind: Scheduled
queryFrequency: 1h
severity: Medium
status: Available
description: |
    'Detects when an action was made by a user which last activity was observed more than 30 days ago.'
query: |
  let lbtime_14d = 14d;
  let lbtime_7d = 7d;
  let lbtime_24h = 24h;
  let known_users_14d = OracleDatabaseAuditEvent
  | where TimeGenerated between (ago(lbtime_14d) .. ago(lbtime_14d))
  | where isnotempty(DstUserName)
  | where isnotempty(Action)
  | summarize makeset(DstUserName);
  let known_users_7d = OracleDatabaseAuditEvent
  | where TimeGenerated between (ago(lbtime_7d) .. ago(lbtime_24h))
  | where isnotempty(DstUserName)
  | where isnotempty(Action)
  | summarize makeset(DstUserName);
  OracleDatabaseAuditEvent
  | where isnotempty(DstUserName)
  | where isnotempty(Action)
  | where DstUserName !in (known_users_7d)
  | where DstUserName in (known_users_14d)
  | project DstUserName
  | extend AccountCustomEntity = DstUserName  
triggerOperator: gt

{
  "$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/5e93a535-036b-4570-9e58-d8992f30e1ae')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/5e93a535-036b-4570-9e58-d8992f30e1ae')]",
      "properties": {
        "alertRuleTemplateName": "5e93a535-036b-4570-9e58-d8992f30e1ae",
        "customDetails": null,
        "description": "'Detects when an action was made by a user which last activity was observed more than 30 days ago.'\n",
        "displayName": "OracleDBAudit - User activity after long inactivity time",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "AccountCustomEntity",
                "identifier": "FullName"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/OracleDatabaseAudit/Analytic Rules/OracleDBAuditRareUserActivity.yaml",
        "query": "let lbtime_14d = 14d;\nlet lbtime_7d = 7d;\nlet lbtime_24h = 24h;\nlet known_users_14d = OracleDatabaseAuditEvent\n| where TimeGenerated between (ago(lbtime_14d) .. ago(lbtime_14d))\n| where isnotempty(DstUserName)\n| where isnotempty(Action)\n| summarize makeset(DstUserName);\nlet known_users_7d = OracleDatabaseAuditEvent\n| where TimeGenerated between (ago(lbtime_7d) .. ago(lbtime_24h))\n| where isnotempty(DstUserName)\n| where isnotempty(Action)\n| summarize makeset(DstUserName);\nOracleDatabaseAuditEvent\n| where isnotempty(DstUserName)\n| where isnotempty(Action)\n| where DstUserName !in (known_users_7d)\n| where DstUserName in (known_users_14d)\n| project DstUserName\n| extend AccountCustomEntity = DstUserName\n",
        "queryFrequency": "PT1H",
        "queryPeriod": "P14D",
        "severity": "Medium",
        "status": "Available",
        "subTechniques": [],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "InitialAccess",
          "Persistence"
        ],
        "techniques": [
          "T1078"
        ],
        "templateVersion": "1.0.1",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}