Dev-0530 File Extension Rename

union isfuzzy=true
    (DeviceFileEvents
    | where ActionType == "FileCreated"
    | where FileName endswith ".h0lyenc" or FolderPath == "C:\\FOR_DECRYPT.html"
    | summarize StartTime = min(TimeGenerated), EndTime = max(TimeGenerated)
        by
        AccountName = InitiatingProcessAccountName, AccountDomain = InitiatingProcessAccountDomain,
        DeviceName,
        Type,
        InitiatingProcessId,
        FileName,
        FolderPath,
        EventType = ActionType,
        Commandline = InitiatingProcessCommandLine,
        InitiatingProcessFileName,
        InitiatingProcessSHA256,
        FileHashCustomEntity = SHA256,
        AlgorithmCustomEntity = "SHA256"
    | extend HostName = tostring(split(DeviceName, ".")[0]), DomainIndex = toint(indexof(DeviceName, '.'))
    | extend HostNameDomain = iff(DomainIndex != -1, substring(DeviceName, DomainIndex + 1), DeviceName)
    ),
    (imFileEvent
    | where EventType == "FileCreated"
    | where TargetFilePath endswith ".h0lyenc" or TargetFilePath == "C:\\FOR_DECRYPT.html"
    | summarize StartTime = min(TimeGenerated), EndTime = max(TimeGenerated)
        by
        ActorUsername,
        DvcHostname,
        DvcDomain,
        DvcId,
        Type,
        EventType,
        FileHashCustomEntity = TargetFileSHA256,
        Hash,
        TargetFilePath,
        Commandline = ActingProcessCommandLine,
        AlgorithmCustomEntity = "SHA256"
    | extend AccountName = tostring(split(ActorUsername, @'\')[1]), AccountDomain = tostring(split(ActorUsername, @'\')[0])
    | extend HostName = DvcHostname, HostNameDomain = DvcDomain
    | extend DeviceName = strcat(DvcHostname, ".", DvcDomain )
    )

entityMappings:
- fieldMappings:
  - identifier: FullName
    columnName: ActorUserName
  - identifier: Name
    columnName: AccountName
  - identifier: NTDomain
    columnName: AccountDomain
  entityType: Account
- fieldMappings:
  - identifier: FullName
    columnName: DeviceName
  - identifier: HostName
    columnName: HostName
  - identifier: DnsDomain
    columnName: HostNameDomain
  entityType: Host
- fieldMappings:
  - identifier: Algorithm
    columnName: AlgorithmCustomEntity
  - identifier: Value
    columnName: FileHashCustomEntity
  entityType: FileHash
metadata:
  categories:
    domains:
    - Security - Others
  support:
    tier: Community
  source:
    kind: Community
  author:
    name: Microsoft Security Research
id: d82eb796-d1eb-43c8-a813-325ce3417cef
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Detections/MultipleDataSources/Dev-0530_FileExtRename.yaml
tactics:
- Impact
kind: Scheduled
requiredDataConnectors:
- dataTypes:
  - DeviceFileEvents
  connectorId: MicrosoftThreatProtection
queryPeriod: 1d
severity: High
relevantTechniques:
- T1486
triggerThreshold: 0
version: 1.1.1
name: Dev-0530 File Extension Rename
triggerOperator: gt
query: |
  union isfuzzy=true
      (DeviceFileEvents
      | where ActionType == "FileCreated"
      | where FileName endswith ".h0lyenc" or FolderPath == "C:\\FOR_DECRYPT.html"
      | summarize StartTime = min(TimeGenerated), EndTime = max(TimeGenerated)
          by
          AccountName = InitiatingProcessAccountName, AccountDomain = InitiatingProcessAccountDomain,
          DeviceName,
          Type,
          InitiatingProcessId,
          FileName,
          FolderPath,
          EventType = ActionType,
          Commandline = InitiatingProcessCommandLine,
          InitiatingProcessFileName,
          InitiatingProcessSHA256,
          FileHashCustomEntity = SHA256,
          AlgorithmCustomEntity = "SHA256"
      | extend HostName = tostring(split(DeviceName, ".")[0]), DomainIndex = toint(indexof(DeviceName, '.'))
      | extend HostNameDomain = iff(DomainIndex != -1, substring(DeviceName, DomainIndex + 1), DeviceName)
      ),
      (imFileEvent
      | where EventType == "FileCreated"
      | where TargetFilePath endswith ".h0lyenc" or TargetFilePath == "C:\\FOR_DECRYPT.html"
      | summarize StartTime = min(TimeGenerated), EndTime = max(TimeGenerated)
          by
          ActorUsername,
          DvcHostname,
          DvcDomain,
          DvcId,
          Type,
          EventType,
          FileHashCustomEntity = TargetFileSHA256,
          Hash,
          TargetFilePath,
          Commandline = ActingProcessCommandLine,
          AlgorithmCustomEntity = "SHA256"
      | extend AccountName = tostring(split(ActorUsername, @'\')[1]), AccountDomain = tostring(split(ActorUsername, @'\')[0])
      | extend HostName = DvcHostname, HostNameDomain = DvcDomain
      | extend DeviceName = strcat(DvcHostname, ".", DvcDomain )
      )
description: |
  'Dev-0530 actors are known to encrypt the contents of the victims device as well as renaming the file extensions. This query looks for the creation of files with .h0lyenc extension or presence of ransom note.'
queryFrequency: 1d
tags:
- Dev-0530
- SchemaVersion: 0.1.0
  Schema: ASIMFileEvent

{
  "$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/d82eb796-d1eb-43c8-a813-325ce3417cef')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/d82eb796-d1eb-43c8-a813-325ce3417cef')]",
      "properties": {
        "alertRuleTemplateName": "d82eb796-d1eb-43c8-a813-325ce3417cef",
        "customDetails": null,
        "description": "'Dev-0530 actors are known to encrypt the contents of the victims device as well as renaming the file extensions. This query looks for the creation of files with .h0lyenc extension or presence of ransom note.'\n",
        "displayName": "Dev-0530 File Extension Rename",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "ActorUserName",
                "identifier": "FullName"
              },
              {
                "columnName": "AccountName",
                "identifier": "Name"
              },
              {
                "columnName": "AccountDomain",
                "identifier": "NTDomain"
              }
            ]
          },
          {
            "entityType": "Host",
            "fieldMappings": [
              {
                "columnName": "DeviceName",
                "identifier": "FullName"
              },
              {
                "columnName": "HostName",
                "identifier": "HostName"
              },
              {
                "columnName": "HostNameDomain",
                "identifier": "DnsDomain"
              }
            ]
          },
          {
            "entityType": "FileHash",
            "fieldMappings": [
              {
                "columnName": "AlgorithmCustomEntity",
                "identifier": "Algorithm"
              },
              {
                "columnName": "FileHashCustomEntity",
                "identifier": "Value"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Detections/MultipleDataSources/Dev-0530_FileExtRename.yaml",
        "query": "union isfuzzy=true\n    (DeviceFileEvents\n    | where ActionType == \"FileCreated\"\n    | where FileName endswith \".h0lyenc\" or FolderPath == \"C:\\\\FOR_DECRYPT.html\"\n    | summarize StartTime = min(TimeGenerated), EndTime = max(TimeGenerated)\n        by\n        AccountName = InitiatingProcessAccountName, AccountDomain = InitiatingProcessAccountDomain,\n        DeviceName,\n        Type,\n        InitiatingProcessId,\n        FileName,\n        FolderPath,\n        EventType = ActionType,\n        Commandline = InitiatingProcessCommandLine,\n        InitiatingProcessFileName,\n        InitiatingProcessSHA256,\n        FileHashCustomEntity = SHA256,\n        AlgorithmCustomEntity = \"SHA256\"\n    | extend HostName = tostring(split(DeviceName, \".\")[0]), DomainIndex = toint(indexof(DeviceName, '.'))\n    | extend HostNameDomain = iff(DomainIndex != -1, substring(DeviceName, DomainIndex + 1), DeviceName)\n    ),\n    (imFileEvent\n    | where EventType == \"FileCreated\"\n    | where TargetFilePath endswith \".h0lyenc\" or TargetFilePath == \"C:\\\\FOR_DECRYPT.html\"\n    | summarize StartTime = min(TimeGenerated), EndTime = max(TimeGenerated)\n        by\n        ActorUsername,\n        DvcHostname,\n        DvcDomain,\n        DvcId,\n        Type,\n        EventType,\n        FileHashCustomEntity = TargetFileSHA256,\n        Hash,\n        TargetFilePath,\n        Commandline = ActingProcessCommandLine,\n        AlgorithmCustomEntity = \"SHA256\"\n    | extend AccountName = tostring(split(ActorUsername, @'\\')[1]), AccountDomain = tostring(split(ActorUsername, @'\\')[0])\n    | extend HostName = DvcHostname, HostNameDomain = DvcDomain\n    | extend DeviceName = strcat(DvcHostname, \".\", DvcDomain )\n    )\n",
        "queryFrequency": "P1D",
        "queryPeriod": "P1D",
        "severity": "High",
        "subTechniques": [],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "Impact"
        ],
        "tags": [
          "Dev-0530",
          {
            "Schema": "ASIMFileEvent",
            "SchemaVersion": "0.1.0"
          }
        ],
        "techniques": [
          "T1486"
        ],
        "templateVersion": "1.1.1",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}