DEV-0270 New User Creation

(union isfuzzy=true
(SecurityEvent
| where EventID == 4688
| where CommandLine has_all ('net user', '/add') 
| parse CommandLine with * "user " username " "*
| extend password = extract(@"\buser\s+[^\s]+\s+([^\s]+)", 1, CommandLine) 
| where username in('DefaultAccount') or password in('P@ssw0rd1234', '_AS_@1394') 
| project TimeGenerated, Computer, Account, AccountDomain, ProcessName, ProcessNameFullPath = NewProcessName, EventID, Activity, CommandLine, EventSourceName, Type
),
(DeviceProcessEvents 
| where InitiatingProcessCommandLine has_all('net user', '/add') 
| parse InitiatingProcessCommandLine with * "user " username " "* 
| extend password = extract(@"\buser\s+[^\s]+\s+([^\s]+)", 1, InitiatingProcessCommandLine) 
| where username in('DefaultAccount') or password in('P@ssw0rd1234', '_AS_@1394') 
| extend Account = strcat(InitiatingProcessAccountDomain, @'\', InitiatingProcessAccountName), Computer = DeviceName
)
)
| extend HostName = tostring(split(Computer, ".")[0]), DomainIndex = toint(indexof(Computer, '.'))
| extend HostNameDomain = iff(DomainIndex != -1, substring(Computer, DomainIndex + 1), Computer)
| extend AccountName = tostring(split(Account, @'\')[1]), AccountNTDomain = tostring(split(Account, @'\')[0])

description: |
    'The following query tries to detect creation of a new user using a known DEV-0270 username/password schema'
status: Available
queryPeriod: 6h
severity: High
triggerOperator: gt
tags:
- Dev-0270
triggerThreshold: 0
version: 1.0.2
name: DEV-0270 New User Creation
queryFrequency: 6h
kind: Scheduled
id: 7965f0be-c039-4d18-8ee8-9a6add8aecf3
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Dev 0270 Detection and Hunting/Analytic Rules/Dev-0270NewUserSep2022.yaml
entityMappings:
- fieldMappings:
  - columnName: Account
    identifier: FullName
  - columnName: AccountName
    identifier: Name
  - columnName: AccountNTDomain
    identifier: NTDomain
  entityType: Account
- fieldMappings:
  - columnName: Computer
    identifier: FullName
  - columnName: HostName
    identifier: HostName
  - columnName: HostNameDomain
    identifier: DnsDomain
  entityType: Host
relevantTechniques:
- T1098
tactics:
- Persistence
requiredDataConnectors:
- dataTypes:
  - SecurityEvent
  connectorId: SecurityEvents
- dataTypes:
  - DeviceProcessEvents
  connectorId: MicrosoftThreatProtection
query: |
  (union isfuzzy=true
  (SecurityEvent
  | where EventID == 4688
  | where CommandLine has_all ('net user', '/add') 
  | parse CommandLine with * "user " username " "*
  | extend password = extract(@"\buser\s+[^\s]+\s+([^\s]+)", 1, CommandLine) 
  | where username in('DefaultAccount') or password in('P@ssw0rd1234', '_AS_@1394') 
  | project TimeGenerated, Computer, Account, AccountDomain, ProcessName, ProcessNameFullPath = NewProcessName, EventID, Activity, CommandLine, EventSourceName, Type
  ),
  (DeviceProcessEvents 
  | where InitiatingProcessCommandLine has_all('net user', '/add') 
  | parse InitiatingProcessCommandLine with * "user " username " "* 
  | extend password = extract(@"\buser\s+[^\s]+\s+([^\s]+)", 1, InitiatingProcessCommandLine) 
  | where username in('DefaultAccount') or password in('P@ssw0rd1234', '_AS_@1394') 
  | extend Account = strcat(InitiatingProcessAccountDomain, @'\', InitiatingProcessAccountName), Computer = DeviceName
  )
  )
  | extend HostName = tostring(split(Computer, ".")[0]), DomainIndex = toint(indexof(Computer, '.'))
  | extend HostNameDomain = iff(DomainIndex != -1, substring(Computer, DomainIndex + 1), Computer)
  | extend AccountName = tostring(split(Account, @'\')[1]), AccountNTDomain = tostring(split(Account, @'\')[0])  

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "workspace": {
      "type": "String"
    }
  },
  "resources": [
    {
      "apiVersion": "2023-02-01-preview",
      "id": "[concat(resourceId('Microsoft.OperationalInsights/workspaces/providers', parameters('workspace'), 'Microsoft.SecurityInsights'),'/alertRules/7965f0be-c039-4d18-8ee8-9a6add8aecf3')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/7965f0be-c039-4d18-8ee8-9a6add8aecf3')]",
      "properties": {
        "alertRuleTemplateName": "7965f0be-c039-4d18-8ee8-9a6add8aecf3",
        "customDetails": null,
        "description": "'The following query tries to detect creation of a new user using a known DEV-0270 username/password schema'\n",
        "displayName": "DEV-0270 New User Creation",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "Account",
                "identifier": "FullName"
              },
              {
                "columnName": "AccountName",
                "identifier": "Name"
              },
              {
                "columnName": "AccountNTDomain",
                "identifier": "NTDomain"
              }
            ]
          },
          {
            "entityType": "Host",
            "fieldMappings": [
              {
                "columnName": "Computer",
                "identifier": "FullName"
              },
              {
                "columnName": "HostName",
                "identifier": "HostName"
              },
              {
                "columnName": "HostNameDomain",
                "identifier": "DnsDomain"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Dev 0270 Detection and Hunting/Analytic Rules/Dev-0270NewUserSep2022.yaml",
        "query": "(union isfuzzy=true\n(SecurityEvent\n| where EventID == 4688\n| where CommandLine has_all ('net user', '/add') \n| parse CommandLine with * \"user \" username \" \"*\n| extend password = extract(@\"\\buser\\s+[^\\s]+\\s+([^\\s]+)\", 1, CommandLine) \n| where username in('DefaultAccount') or password in('P@ssw0rd1234', '_AS_@1394') \n| project TimeGenerated, Computer, Account, AccountDomain, ProcessName, ProcessNameFullPath = NewProcessName, EventID, Activity, CommandLine, EventSourceName, Type\n),\n(DeviceProcessEvents \n| where InitiatingProcessCommandLine has_all('net user', '/add') \n| parse InitiatingProcessCommandLine with * \"user \" username \" \"* \n| extend password = extract(@\"\\buser\\s+[^\\s]+\\s+([^\\s]+)\", 1, InitiatingProcessCommandLine) \n| where username in('DefaultAccount') or password in('P@ssw0rd1234', '_AS_@1394') \n| extend Account = strcat(InitiatingProcessAccountDomain, @'\\', InitiatingProcessAccountName), Computer = DeviceName\n)\n)\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(Account, @'\\')[1]), AccountNTDomain = tostring(split(Account, @'\\')[0])\n",
        "queryFrequency": "PT6H",
        "queryPeriod": "PT6H",
        "severity": "High",
        "status": "Available",
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "Persistence"
        ],
        "tags": [
          "Dev-0270"
        ],
        "techniques": [
          "T1098"
        ],
        "templateVersion": "1.0.2",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}