Match Legitimate Name or Location - 2

let ProcessRelations=datatable(ImageFile:string,ExpectedParent:dynamic) [
  "smss.exe", dynamic(["smss.exe", "ntoskrnl.exe", ""]),
  "crmss.exe", dynamic(["smss.exe"]),
  "wininit.exe", dynamic(["smss.exe"]),
  "winlogon.exe", dynamic(["smss.exe"]),
  "services.exe", dynamic(["wininit.exe"]),
  "lsaiso.exe", dynamic(["wininit.exe"]),
  "lsass.exe", dynamic(["wininit.exe"]),
  "spoolsv.exe", dynamic(["services.exe"]),
  "dllhost.exe", dynamic(["svchost.exe", "services.exe"]),
  "lsm.exe", dynamic(["wininit.exe"]),
  "svchost.exe", dynamic(["services.exe", "msmpeng.exe"]),
  "runtimebroker.exe", dynamic(["svchost.exe"]),
  "taskhostw.exe", dynamic(["svchost.exe"]),
  "userinit.exe", dynamic(["winlogon.exe"])
  // Explorer can have a lot of parents in some environments
  //,"explorer.exe", dynamic(["userinit.exe"])
];
DeviceProcessEvents
| extend ImageFile = tostring(tolower(parse_path(tostring(FolderPath)).Filename))
| extend ParentFile = tostring(tolower(parse_path(tostring(InitiatingProcessFolderPath)).Filename))
| lookup kind=inner ProcessRelations on ImageFile
| where not(set_has_element(ExpectedParent,ParentFile))

version: 1.0.1
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/FalconFriday/Analytic%20Rules/MatchLegitimateNameOrLocation.yaml
triggerThreshold: 0
requiredDataConnectors:
- dataTypes:
  - DeviceProcessEvents
  connectorId: MicrosoftThreatProtection
tactics:
- DefenseEvasion
relevantTechniques:
- T1036.005
kind: Scheduled
entityMappings:
- fieldMappings:
  - identifier: FullName
    columnName: DeviceName
  entityType: Host
- fieldMappings:
  - identifier: Sid
    columnName: AccountSid
  - identifier: Name
    columnName: AccountName
  - identifier: NTDomain
    columnName: AccountDomain
  entityType: Account
- fieldMappings:
  - identifier: CommandLine
    columnName: ProcessCommandLine
  entityType: Process
description: |
  Attackers often match or approximate the name or location of legitimate files to avoid detection rules that are based trust of on certain operating system processes.
  This query detects mismatches in the parent-child relationship of core operating system processes to uncover different masquerading attempts.
triggerOperator: gt
status: Available
queryFrequency: 1h
id: dd22dc4f-ab7c-4d0a-84ad-cc393638ba31
name: Match Legitimate Name or Location - 2
severity: Medium
query: |
  let ProcessRelations=datatable(ImageFile:string,ExpectedParent:dynamic) [
    "smss.exe", dynamic(["smss.exe", "ntoskrnl.exe", ""]),
    "crmss.exe", dynamic(["smss.exe"]),
    "wininit.exe", dynamic(["smss.exe"]),
    "winlogon.exe", dynamic(["smss.exe"]),
    "services.exe", dynamic(["wininit.exe"]),
    "lsaiso.exe", dynamic(["wininit.exe"]),
    "lsass.exe", dynamic(["wininit.exe"]),
    "spoolsv.exe", dynamic(["services.exe"]),
    "dllhost.exe", dynamic(["svchost.exe", "services.exe"]),
    "lsm.exe", dynamic(["wininit.exe"]),
    "svchost.exe", dynamic(["services.exe", "msmpeng.exe"]),
    "runtimebroker.exe", dynamic(["svchost.exe"]),
    "taskhostw.exe", dynamic(["svchost.exe"]),
    "userinit.exe", dynamic(["winlogon.exe"])
    // Explorer can have a lot of parents in some environments
    //,"explorer.exe", dynamic(["userinit.exe"])
  ];
  DeviceProcessEvents
  | extend ImageFile = tostring(tolower(parse_path(tostring(FolderPath)).Filename))
  | extend ParentFile = tostring(tolower(parse_path(tostring(InitiatingProcessFolderPath)).Filename))
  | lookup kind=inner ProcessRelations on ImageFile
  | where not(set_has_element(ExpectedParent,ParentFile))
queryPeriod: 1h

{
  "$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/dd22dc4f-ab7c-4d0a-84ad-cc393638ba31')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/dd22dc4f-ab7c-4d0a-84ad-cc393638ba31')]",
      "properties": {
        "alertRuleTemplateName": "dd22dc4f-ab7c-4d0a-84ad-cc393638ba31",
        "customDetails": null,
        "description": "Attackers often match or approximate the name or location of legitimate files to avoid detection rules that are based trust of on certain operating system processes.\nThis query detects mismatches in the parent-child relationship of core operating system processes to uncover different masquerading attempts.\n",
        "displayName": "Match Legitimate Name or Location - 2",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "Host",
            "fieldMappings": [
              {
                "columnName": "DeviceName",
                "identifier": "FullName"
              }
            ]
          },
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "AccountSid",
                "identifier": "Sid"
              },
              {
                "columnName": "AccountName",
                "identifier": "Name"
              },
              {
                "columnName": "AccountDomain",
                "identifier": "NTDomain"
              }
            ]
          },
          {
            "entityType": "Process",
            "fieldMappings": [
              {
                "columnName": "ProcessCommandLine",
                "identifier": "CommandLine"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/FalconFriday/Analytic%20Rules/MatchLegitimateNameOrLocation.yaml",
        "query": "let ProcessRelations=datatable(ImageFile:string,ExpectedParent:dynamic) [\n  \"smss.exe\", dynamic([\"smss.exe\", \"ntoskrnl.exe\", \"\"]),\n  \"crmss.exe\", dynamic([\"smss.exe\"]),\n  \"wininit.exe\", dynamic([\"smss.exe\"]),\n  \"winlogon.exe\", dynamic([\"smss.exe\"]),\n  \"services.exe\", dynamic([\"wininit.exe\"]),\n  \"lsaiso.exe\", dynamic([\"wininit.exe\"]),\n  \"lsass.exe\", dynamic([\"wininit.exe\"]),\n  \"spoolsv.exe\", dynamic([\"services.exe\"]),\n  \"dllhost.exe\", dynamic([\"svchost.exe\", \"services.exe\"]),\n  \"lsm.exe\", dynamic([\"wininit.exe\"]),\n  \"svchost.exe\", dynamic([\"services.exe\", \"msmpeng.exe\"]),\n  \"runtimebroker.exe\", dynamic([\"svchost.exe\"]),\n  \"taskhostw.exe\", dynamic([\"svchost.exe\"]),\n  \"userinit.exe\", dynamic([\"winlogon.exe\"])\n  // Explorer can have a lot of parents in some environments\n  //,\"explorer.exe\", dynamic([\"userinit.exe\"])\n];\nDeviceProcessEvents\n| extend ImageFile = tostring(tolower(parse_path(tostring(FolderPath)).Filename))\n| extend ParentFile = tostring(tolower(parse_path(tostring(InitiatingProcessFolderPath)).Filename))\n| lookup kind=inner ProcessRelations on ImageFile\n| where not(set_has_element(ExpectedParent,ParentFile))\n",
        "queryFrequency": "PT1H",
        "queryPeriod": "PT1H",
        "severity": "Medium",
        "status": "Available",
        "subTechniques": [
          "T1036.005"
        ],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "DefenseEvasion"
        ],
        "techniques": [
          "T1036"
        ],
        "templateVersion": "1.0.1",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}