Security Event log cleared | Microsoft Sentinel Analytic Rules

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Id	80da0a8f-cfe1-4cd0-a895-8bc1771a720e
Rulename	Security Event log cleared
Description	Checks for event id 1102 which indicates the security event log was cleared. It uses Event Source Name “Microsoft-Windows-Eventlog” to avoid generating false positives from other sources, like AD FS servers for instance.
Severity	Medium
Tactics	DefenseEvasion
Techniques	T1070
Required data connectors	SecurityEvents WindowsForwardedEvents WindowsSecurityEvents
Kind	Scheduled
Query frequency	1d
Query period	1d
Trigger threshold	0
Trigger operator	gt
Source Uri	https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Endpoint%20Threat%20Protection%20Essentials/Analytic%20Rules/SecurityEventLogCleared.yaml
Version	1.1.5
Arm template	80da0a8f-cfe1-4cd0-a895-8bc1771a720e.json

KQL

(union isfuzzy=true
(
SecurityEvent
| where EventID == 1102 and EventSourceName =~ "Microsoft-Windows-Eventlog"
| summarize StartTimeUtc = min(TimeGenerated), EndTimeUtc = max(TimeGenerated), EventCount = count() by Computer, Account, EventID, Activity
),
(
WindowsEvent
| where EventID == 1102 and Provider =~ "Microsoft-Windows-Eventlog"
| extend Account =  strcat(tostring(EventData.SubjectDomainName),"\\", tostring(EventData.SubjectUserName))
| extend Activity= "1102 - The audit log was cleared."
| summarize StartTimeUtc = min(TimeGenerated), EndTimeUtc = max(TimeGenerated), EventCount = count() by Computer, Account, EventID, Activity
)
)
| extend Name=tostring(split(Account, "@")[0]), UPNSuffix=tostring(split(Account, "@")[1])
| extend HostName = iif(Computer has '.',substring(Computer,0,indexof(Computer,'.')),Computer) , DnsDomain = iif(Computer has '.',substring(Computer,indexof(Computer,'.')+1),'')

YAML

id: 80da0a8f-cfe1-4cd0-a895-8bc1771a720e
triggerThreshold: 0
description: |
  'Checks for event id 1102 which indicates the security event log was cleared.
  It uses Event Source Name "Microsoft-Windows-Eventlog" to avoid generating false positives from other sources, like AD FS servers for instance.'
tactics:
- DefenseEvasion
kind: Scheduled
queryPeriod: 1d
name: Security Event log cleared
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Endpoint%20Threat%20Protection%20Essentials/Analytic%20Rules/SecurityEventLogCleared.yaml
version: 1.1.5
queryFrequency: 1d
query: |
  (union isfuzzy=true
  (
  SecurityEvent
  | where EventID == 1102 and EventSourceName =~ "Microsoft-Windows-Eventlog"
  | summarize StartTimeUtc = min(TimeGenerated), EndTimeUtc = max(TimeGenerated), EventCount = count() by Computer, Account, EventID, Activity
  ),
  (
  WindowsEvent
  | where EventID == 1102 and Provider =~ "Microsoft-Windows-Eventlog"
  | extend Account =  strcat(tostring(EventData.SubjectDomainName),"\\", tostring(EventData.SubjectUserName))
  | extend Activity= "1102 - The audit log was cleared."
  | summarize StartTimeUtc = min(TimeGenerated), EndTimeUtc = max(TimeGenerated), EventCount = count() by Computer, Account, EventID, Activity
  )
  )
  | extend Name=tostring(split(Account, "@")[0]), UPNSuffix=tostring(split(Account, "@")[1])
  | extend HostName = iif(Computer has '.',substring(Computer,0,indexof(Computer,'.')),Computer) , DnsDomain = iif(Computer has '.',substring(Computer,indexof(Computer,'.')+1),'')
entityMappings:
- fieldMappings:
  - columnName: Name
    identifier: Name
  - columnName: UPNSuffix
    identifier: UPNSuffix
  entityType: Account
- fieldMappings:
  - columnName: Computer
    identifier: FullName
  - columnName: HostName
    identifier: HostName
  - columnName: DnsDomain
    identifier: DnsDomain
  entityType: Host
severity: Medium
requiredDataConnectors:
- connectorId: SecurityEvents
  dataTypes:
  - SecurityEvent
- connectorId: WindowsSecurityEvents
  dataTypes:
  - SecurityEvent
- connectorId: WindowsForwardedEvents
  dataTypes:
  - WindowsEvent
triggerOperator: gt
status: Available
relevantTechniques:
- T1070

ARM

{
  "$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/80da0a8f-cfe1-4cd0-a895-8bc1771a720e')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/80da0a8f-cfe1-4cd0-a895-8bc1771a720e')]",
      "properties": {
        "alertRuleTemplateName": "80da0a8f-cfe1-4cd0-a895-8bc1771a720e",
        "customDetails": null,
        "description": "'Checks for event id 1102 which indicates the security event log was cleared.\nIt uses Event Source Name \"Microsoft-Windows-Eventlog\" to avoid generating false positives from other sources, like AD FS servers for instance.'\n",
        "displayName": "Security Event log cleared",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "Name",
                "identifier": "Name"
              },
              {
                "columnName": "UPNSuffix",
                "identifier": "UPNSuffix"
              }
            ]
          },
          {
            "entityType": "Host",
            "fieldMappings": [
              {
                "columnName": "Computer",
                "identifier": "FullName"
              },
              {
                "columnName": "HostName",
                "identifier": "HostName"
              },
              {
                "columnName": "DnsDomain",
                "identifier": "DnsDomain"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Endpoint%20Threat%20Protection%20Essentials/Analytic%20Rules/SecurityEventLogCleared.yaml",
        "query": "(union isfuzzy=true\n(\nSecurityEvent\n| where EventID == 1102 and EventSourceName =~ \"Microsoft-Windows-Eventlog\"\n| summarize StartTimeUtc = min(TimeGenerated), EndTimeUtc = max(TimeGenerated), EventCount = count() by Computer, Account, EventID, Activity\n),\n(\nWindowsEvent\n| where EventID == 1102 and Provider =~ \"Microsoft-Windows-Eventlog\"\n| extend Account =  strcat(tostring(EventData.SubjectDomainName),\"\\\\\", tostring(EventData.SubjectUserName))\n| extend Activity= \"1102 - The audit log was cleared.\"\n| summarize StartTimeUtc = min(TimeGenerated), EndTimeUtc = max(TimeGenerated), EventCount = count() by Computer, Account, EventID, Activity\n)\n)\n| extend Name=tostring(split(Account, \"@\")[0]), UPNSuffix=tostring(split(Account, \"@\")[1])\n| extend HostName = iif(Computer has '.',substring(Computer,0,indexof(Computer,'.')),Computer) , DnsDomain = iif(Computer has '.',substring(Computer,indexof(Computer,'.')+1),'')\n",
        "queryFrequency": "P1D",
        "queryPeriod": "P1D",
        "severity": "Medium",
        "status": "Available",
        "subTechniques": [],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "DefenseEvasion"
        ],
        "techniques": [
          "T1070"
        ],
        "templateVersion": "1.1.5",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}