Deletion of data on multiple drives using cipher exe | Microsoft Sentinel Analytic Rules

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Id	03caa992-477f-4b19-8e2a-8cd58f8f9652
Rulename	Deletion of data on multiple drives using cipher exe
Description	This query checks for attempts to delete data on multiple drives using cipher.exe. This activity is typically done by ransomware to prevent recovery of data after encryption.
Severity	Medium
Tactics	Impact
Techniques	T1485
Required data connectors	MicrosoftThreatProtection
Kind	Scheduled
Query frequency	1h
Query period	1h
Trigger threshold	0
Trigger operator	gt
Source Uri	https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Microsoft%20Defender%20XDR/Analytic%20Rules/Ransomware/DataDeletionOnMulipleDrivesUsingCipherExe.yaml
Version	1.0.0
Arm template	03caa992-477f-4b19-8e2a-8cd58f8f9652.json

KQL

// Look for cipher.exe deleting data from multiple drives
DeviceProcessEvents
| where FileName =~ "cipher.exe" 
// cipher.exe /w flag used for deleting data 
| where ProcessCommandLine has "/w" 
| summarize CipherCount = dcount(ProcessCommandLine), CipherList = make_set(ProcessCommandLine, 1000) by DeviceId, DeviceName, bin(TimeGenerated, 1m) 
// cipher.exe accessing multiple drives in a short timeframe  
| where CipherCount > 1
| extend HostName = iff(DeviceName has '.', substring(DeviceName, 0, indexof(DeviceName, '.')), DeviceName)
| extend DnsDomain = iff(DeviceName has '.', substring(DeviceName, indexof(DeviceName, '.') + 1), "")

YAML

entityMappings:
- fieldMappings:
  - identifier: FullName
    columnName: DeviceName
  - identifier: HostName
    columnName: HostName
  - identifier: DnsDomain
    columnName: DnsDomain
  entityType: Host
id: 03caa992-477f-4b19-8e2a-8cd58f8f9652
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Microsoft%20Defender%20XDR/Analytic%20Rules/Ransomware/DataDeletionOnMulipleDrivesUsingCipherExe.yaml
triggerOperator: gt
tactics:
- Impact
kind: Scheduled
requiredDataConnectors:
- dataTypes:
  - DeviceProcessEvents
  connectorId: MicrosoftThreatProtection
queryPeriod: 1h
severity: Medium
relevantTechniques:
- T1485
triggerThreshold: 0
version: 1.0.0
name: Deletion of data on multiple drives using cipher exe
status: Available
query: |
  // Look for cipher.exe deleting data from multiple drives
  DeviceProcessEvents
  | where FileName =~ "cipher.exe" 
  // cipher.exe /w flag used for deleting data 
  | where ProcessCommandLine has "/w" 
  | summarize CipherCount = dcount(ProcessCommandLine), CipherList = make_set(ProcessCommandLine, 1000) by DeviceId, DeviceName, bin(TimeGenerated, 1m) 
  // cipher.exe accessing multiple drives in a short timeframe  
  | where CipherCount > 1
  | extend HostName = iff(DeviceName has '.', substring(DeviceName, 0, indexof(DeviceName, '.')), DeviceName)
  | extend DnsDomain = iff(DeviceName has '.', substring(DeviceName, indexof(DeviceName, '.') + 1), "")
description: |
  This query checks for attempts to delete data on multiple drives using cipher.exe. This activity is typically done by ransomware to prevent recovery of data after encryption.
queryFrequency: 1h

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/03caa992-477f-4b19-8e2a-8cd58f8f9652')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/03caa992-477f-4b19-8e2a-8cd58f8f9652')]",
      "properties": {
        "alertRuleTemplateName": "03caa992-477f-4b19-8e2a-8cd58f8f9652",
        "customDetails": null,
        "description": "This query checks for attempts to delete data on multiple drives using cipher.exe. This activity is typically done by ransomware to prevent recovery of data after encryption.\n",
        "displayName": "Deletion of data on multiple drives using cipher exe",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "Host",
            "fieldMappings": [
              {
                "columnName": "DeviceName",
                "identifier": "FullName"
              },
              {
                "columnName": "HostName",
                "identifier": "HostName"
              },
              {
                "columnName": "DnsDomain",
                "identifier": "DnsDomain"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Microsoft%20Defender%20XDR/Analytic%20Rules/Ransomware/DataDeletionOnMulipleDrivesUsingCipherExe.yaml",
        "query": "// Look for cipher.exe deleting data from multiple drives\nDeviceProcessEvents\n| where FileName =~ \"cipher.exe\" \n// cipher.exe /w flag used for deleting data \n| where ProcessCommandLine has \"/w\" \n| summarize CipherCount = dcount(ProcessCommandLine), CipherList = make_set(ProcessCommandLine, 1000) by DeviceId, DeviceName, bin(TimeGenerated, 1m) \n// cipher.exe accessing multiple drives in a short timeframe  \n| where CipherCount > 1\n| extend HostName = iff(DeviceName has '.', substring(DeviceName, 0, indexof(DeviceName, '.')), DeviceName)\n| extend DnsDomain = iff(DeviceName has '.', substring(DeviceName, indexof(DeviceName, '.') + 1), \"\")\n",
        "queryFrequency": "PT1H",
        "queryPeriod": "PT1H",
        "severity": "Medium",
        "status": "Available",
        "subTechniques": [],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "Impact"
        ],
        "techniques": [
          "T1485"
        ],
        "templateVersion": "1.0.0",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}