AWSCloudTrail - Changes to Amazon VPC settings

let EventNameList = dynamic(["CreateNetworkAclEntry","CreateRoute","CreateRouteTable","CreateInternetGateway","CreateNatGateway"]);
AWSCloudTrail
| where EventName in~ (EventNameList)
| where EventSource != "apigateway.amazonaws.com"
| extend UserIdentityArn = iif(isempty(UserIdentityArn), tostring(parse_json(Resources)[0].ARN), UserIdentityArn)
| extend UserName = tostring(split(UserIdentityArn, '/')[-1])
| extend AccountName = case( UserIdentityPrincipalid == "Anonymous", "Anonymous", isempty(UserIdentityUserName), UserName, UserIdentityUserName)
| extend AccountName = iif(AccountName contains "@", tostring(split(AccountName, '@', 0)[0]), AccountName),
  AccountUPNSuffix = iif(AccountName contains "@", tostring(split(AccountName, '@', 1)[0]), "")
| summarize StartTimeUtc = min(TimeGenerated), EndTimeUtc = max(TimeGenerated) by EventName, EventTypeName, RecipientAccountId, AccountName, AccountUPNSuffix, UserIdentityAccountId, UserIdentityPrincipalid, UserAgent,
UserIdentityUserName, SessionMfaAuthenticated, SourceIpAddress, AWSRegion, EventSource, AdditionalEventData, ResponseElements

alertDetailsOverride:
  alertDescriptionFormat: Event {{EventName}} executed by {{AccountName}} from {{SourceIpAddress}}.
  alertDisplayNameFormat: AWS VPC change by {{AccountName}} in {{AWSRegion}}
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Amazon%20Web%20Services/Analytic%20Rules/AWS_ChangeToVPC.yaml
version: 1.0.8
status: Available
queryPeriod: 1d
name: AWSCloudTrail - Changes to Amazon VPC settings
tactics:
- PrivilegeEscalation
- DefenseEvasion
customDetails:
  RecipientAccountId: RecipientAccountId
  AWSRegion: AWSRegion
  EventSource: EventSource
  EventName: EventName
id: 65360bb0-8986-4ade-a89d-af3cf44d28aa
triggerOperator: gt
query: |
  let EventNameList = dynamic(["CreateNetworkAclEntry","CreateRoute","CreateRouteTable","CreateInternetGateway","CreateNatGateway"]);
  AWSCloudTrail
  | where EventName in~ (EventNameList)
  | where EventSource != "apigateway.amazonaws.com"
  | extend UserIdentityArn = iif(isempty(UserIdentityArn), tostring(parse_json(Resources)[0].ARN), UserIdentityArn)
  | extend UserName = tostring(split(UserIdentityArn, '/')[-1])
  | extend AccountName = case( UserIdentityPrincipalid == "Anonymous", "Anonymous", isempty(UserIdentityUserName), UserName, UserIdentityUserName)
  | extend AccountName = iif(AccountName contains "@", tostring(split(AccountName, '@', 0)[0]), AccountName),
    AccountUPNSuffix = iif(AccountName contains "@", tostring(split(AccountName, '@', 1)[0]), "")
  | summarize StartTimeUtc = min(TimeGenerated), EndTimeUtc = max(TimeGenerated) by EventName, EventTypeName, RecipientAccountId, AccountName, AccountUPNSuffix, UserIdentityAccountId, UserIdentityPrincipalid, UserAgent,
  UserIdentityUserName, SessionMfaAuthenticated, SourceIpAddress, AWSRegion, EventSource, AdditionalEventData, ResponseElements
queryFrequency: 1d
severity: Low
kind: Scheduled
description: |
  Identifies changes to Amazon VPC(Virtual Private Cloud) settings that can alter network exposure, routing, or access controls.
  This rule identifies changes to Amazon VPC (Virtual Private Cloud) settings such as new ACL entries, routes, routetable or Gateways. 
  AWS VPC API Docs: https://docs.aws.amazon.com/AWSEC2/latest/APIReference/OperationList-query-vpc.html'
relevantTechniques:
- T1078
- T1562.007
triggerThreshold: 0
requiredDataConnectors:
- dataTypes:
  - AWSCloudTrail
  connectorId: AWS
- dataTypes:
  - AWSCloudTrail
  connectorId: AWSS3
entityMappings:
- fieldMappings:
  - columnName: AccountName
    identifier: Name
  - columnName: AccountUPNSuffix
    identifier: UPNSuffix
  - columnName: RecipientAccountId
    identifier: CloudAppAccountId
  entityType: Account
- fieldMappings:
  - columnName: SourceIpAddress
    identifier: Address
  entityType: IP

{
  "$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/65360bb0-8986-4ade-a89d-af3cf44d28aa')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/65360bb0-8986-4ade-a89d-af3cf44d28aa')]",
      "properties": {
        "alertDetailsOverride": {
          "alertDescriptionFormat": "Event {{EventName}} executed by {{AccountName}} from {{SourceIpAddress}}.",
          "alertDisplayNameFormat": "AWS VPC change by {{AccountName}} in {{AWSRegion}}"
        },
        "alertRuleTemplateName": "65360bb0-8986-4ade-a89d-af3cf44d28aa",
        "customDetails": {
          "AWSRegion": "AWSRegion",
          "EventName": "EventName",
          "EventSource": "EventSource",
          "RecipientAccountId": "RecipientAccountId"
        },
        "description": "Identifies changes to Amazon VPC(Virtual Private Cloud) settings that can alter network exposure, routing, or access controls.\nThis rule identifies changes to Amazon VPC (Virtual Private Cloud) settings such as new ACL entries, routes, routetable or Gateways. \nAWS VPC API Docs: https://docs.aws.amazon.com/AWSEC2/latest/APIReference/OperationList-query-vpc.html'\n",
        "displayName": "AWSCloudTrail - Changes to Amazon VPC settings",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "AccountName",
                "identifier": "Name"
              },
              {
                "columnName": "AccountUPNSuffix",
                "identifier": "UPNSuffix"
              },
              {
                "columnName": "RecipientAccountId",
                "identifier": "CloudAppAccountId"
              }
            ]
          },
          {
            "entityType": "IP",
            "fieldMappings": [
              {
                "columnName": "SourceIpAddress",
                "identifier": "Address"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Amazon%20Web%20Services/Analytic%20Rules/AWS_ChangeToVPC.yaml",
        "query": "let EventNameList = dynamic([\"CreateNetworkAclEntry\",\"CreateRoute\",\"CreateRouteTable\",\"CreateInternetGateway\",\"CreateNatGateway\"]);\nAWSCloudTrail\n| where EventName in~ (EventNameList)\n| where EventSource != \"apigateway.amazonaws.com\"\n| extend UserIdentityArn = iif(isempty(UserIdentityArn), tostring(parse_json(Resources)[0].ARN), UserIdentityArn)\n| extend UserName = tostring(split(UserIdentityArn, '/')[-1])\n| extend AccountName = case( UserIdentityPrincipalid == \"Anonymous\", \"Anonymous\", isempty(UserIdentityUserName), UserName, UserIdentityUserName)\n| extend AccountName = iif(AccountName contains \"@\", tostring(split(AccountName, '@', 0)[0]), AccountName),\n  AccountUPNSuffix = iif(AccountName contains \"@\", tostring(split(AccountName, '@', 1)[0]), \"\")\n| summarize StartTimeUtc = min(TimeGenerated), EndTimeUtc = max(TimeGenerated) by EventName, EventTypeName, RecipientAccountId, AccountName, AccountUPNSuffix, UserIdentityAccountId, UserIdentityPrincipalid, UserAgent,\nUserIdentityUserName, SessionMfaAuthenticated, SourceIpAddress, AWSRegion, EventSource, AdditionalEventData, ResponseElements\n",
        "queryFrequency": "P1D",
        "queryPeriod": "P1D",
        "severity": "Low",
        "status": "Available",
        "subTechniques": [
          "T1562.007"
        ],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "DefenseEvasion",
          "PrivilegeEscalation"
        ],
        "techniques": [
          "T1078",
          "T1562"
        ],
        "templateVersion": "1.0.8",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}