SUPERNOVA webshell

W3CIISLog
| where csMethod == 'GET'
| where isnotempty(csUriStem) and isnotempty(csUriQuery)
| where csUriStem contains "logoimagehandler.ashx"
| where csUriQuery contains "codes" and csUriQuery contains "clazz" and csUriQuery contains "method" and csUriQuery contains "args"
| extend timestamp = TimeGenerated
| extend HostName = tostring(split(Computer, ".")[0]), DomainIndex = toint(indexof(Computer, '.'))
| extend HostNameDomain = iff(DomainIndex != -1, substring(Computer, DomainIndex + 1), Computer)
| extend AccountName = tostring(split(csUserName, "@")[0]), AccountUPNSuffix = tostring(split(csUserName, "@")[1])

relevantTechniques:
- T1505
- T1071
name: SUPERNOVA webshell
requiredDataConnectors:
- dataTypes:
  - W3CIISLog
  connectorId: AzureMonitor(IIS)
entityMappings:
- fieldMappings:
  - identifier: FullName
    columnName: csUserName
  - identifier: Name
    columnName: AccountName
  - identifier: UPNSuffix
    columnName: AccountUPNSuffix
  entityType: Account
- fieldMappings:
  - identifier: FullName
    columnName: Computer
  - identifier: HostName
    columnName: HostName
  - identifier: DnsDomain
    columnName: HostNameDomain
  entityType: Host
- fieldMappings:
  - identifier: Address
    columnName: cIP
  entityType: IP
triggerThreshold: 0
id: 2acc91c3-17c2-4388-938e-4eac2d5894e8
tactics:
- Persistence
- CommandAndControl
version: 1.0.4
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Web Shells Threat Protection/Analytic Rules/Supernovawebshell.yaml
queryPeriod: 1d
kind: Scheduled
metadata:
  categories:
    domains:
    - Security - Others
  author:
    name: Microsoft Security Research
  support:
    tier: Community
  source:
    kind: Scheduled
queryFrequency: 1d
severity: High
description: |
  'Identifies SUPERNOVA webshell based on W3CIISLog data.
   References:
   - https://unit42.paloaltonetworks.com/solarstorm-supernova/'  
query: |
  W3CIISLog
  | where csMethod == 'GET'
  | where isnotempty(csUriStem) and isnotempty(csUriQuery)
  | where csUriStem contains "logoimagehandler.ashx"
  | where csUriQuery contains "codes" and csUriQuery contains "clazz" and csUriQuery contains "method" and csUriQuery contains "args"
  | extend timestamp = TimeGenerated
  | extend HostName = tostring(split(Computer, ".")[0]), DomainIndex = toint(indexof(Computer, '.'))
  | extend HostNameDomain = iff(DomainIndex != -1, substring(Computer, DomainIndex + 1), Computer)
  | extend AccountName = tostring(split(csUserName, "@")[0]), AccountUPNSuffix = tostring(split(csUserName, "@")[1])  
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/2acc91c3-17c2-4388-938e-4eac2d5894e8')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/2acc91c3-17c2-4388-938e-4eac2d5894e8')]",
      "properties": {
        "alertRuleTemplateName": "2acc91c3-17c2-4388-938e-4eac2d5894e8",
        "customDetails": null,
        "description": "'Identifies SUPERNOVA webshell based on W3CIISLog data.\n References:\n - https://unit42.paloaltonetworks.com/solarstorm-supernova/'\n",
        "displayName": "SUPERNOVA webshell",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "csUserName",
                "identifier": "FullName"
              },
              {
                "columnName": "AccountName",
                "identifier": "Name"
              },
              {
                "columnName": "AccountUPNSuffix",
                "identifier": "UPNSuffix"
              }
            ]
          },
          {
            "entityType": "Host",
            "fieldMappings": [
              {
                "columnName": "Computer",
                "identifier": "FullName"
              },
              {
                "columnName": "HostName",
                "identifier": "HostName"
              },
              {
                "columnName": "HostNameDomain",
                "identifier": "DnsDomain"
              }
            ]
          },
          {
            "entityType": "IP",
            "fieldMappings": [
              {
                "columnName": "cIP",
                "identifier": "Address"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Web Shells Threat Protection/Analytic Rules/Supernovawebshell.yaml",
        "query": "W3CIISLog\n| where csMethod == 'GET'\n| where isnotempty(csUriStem) and isnotempty(csUriQuery)\n| where csUriStem contains \"logoimagehandler.ashx\"\n| where csUriQuery contains \"codes\" and csUriQuery contains \"clazz\" and csUriQuery contains \"method\" and csUriQuery contains \"args\"\n| extend timestamp = TimeGenerated\n| extend HostName = tostring(split(Computer, \".\")[0]), DomainIndex = toint(indexof(Computer, '.'))\n| extend HostNameDomain = iff(DomainIndex != -1, substring(Computer, DomainIndex + 1), Computer)\n| extend AccountName = tostring(split(csUserName, \"@\")[0]), AccountUPNSuffix = tostring(split(csUserName, \"@\")[1])\n",
        "queryFrequency": "P1D",
        "queryPeriod": "P1D",
        "severity": "High",
        "subTechniques": [],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "CommandAndControl",
          "Persistence"
        ],
        "techniques": [
          "T1071",
          "T1505"
        ],
        "templateVersion": "1.0.4",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}