¿Cómo configuro notificaciones de correo electrónico personalizadas para los hallazgos de Security Hub mediante EventBridge con un tema de Amazon SNS?

Última actualización: 11-01-2022

Quiero configurar una notificación por correo electrónico personalizada para los hallazgos de Security Hub mediante Amazon EventBridge y un tema de Amazon Simple Notification Service (Amazon SNS).

Descripción corta

En la siguiente resolución se muestra cómo configurar EventBridge con SNS para recibir notificaciones de Security Hub. Según la regla de EventBridge, Amazon SNS envía una notificación a la dirección o direcciones de correo electrónico suscritas al tema cuando se produce el evento. El mensaje generado puede resultar difícil de leer debido a su formato. Sin embargo, la inclusión de una función de AWS Lambda crea un mensaje de alerta personalizado con un formato mejorado antes de enviarlo a los suscriptores de SNS.

Para crear una notificación por correo electrónico personalizada, haga lo siguiente:

1.    Cree los siguientes destinos de reglas de EventBridge:
Un tema de SNS y suscripciones de correo electrónico.
Una función Lambda.

2.    Cree una regla de EventBridge.

3.    Reciba una notificación personalizada.

Importante: La siguiente resolución utiliza eventos de AWS Security Hub y una función Lambda para la personalización. Para obtener más información sobre los costes asociados, consulte los precios de AWS Security Hub y los precios de AWS Lambda.

Resolución

Crear un tema y una suscripción de SNS

1.    Abra la consola de Amazon SNS.

2.    En el panel de navegación, elija Topics (Temas).

3.    Elija Create topic (Crear tema).

4.    En la sección Details (Detalles), para Type (Tipo), elija Standard (Estándar).

5.    En Name (Nombre), ingrese el nombre de su tema.

6.    Elija Create topic (Crear tema).

7.    En el tema creado, elija Create subscription (Crear suscripción).

8.    Para Topic ARN (ARN de tema), seleccione el nombre de recurso de Amazon (ARN) del tema que creó si no se rellena automáticamente.

9.    En Protocol (Protocolo), ingrese Email (Correo electrónico).

10.    En Endpoint (Punto de conexión), ingrese la dirección de correo electrónico en la que desea recibir las notificaciones de SNS.

11.    Elija Create subscription (Crear suscripción).

Importante: Debe confirmar la suscripción en el correo electrónico de confirmación enviado al suscriptor para que la suscripción cambie del estado PendingConfirmation (Pendiente de confirmación) a Confirmed (Confirmada).

Nota: (Opcional) también puede crear una suscripción autenticada que impida la acción de cancelación de suscripción en su tema.

Crear una función Lambda

Cree una función de Lambda que extraiga la información que desea del contenido JSON y publique un mensaje personalizado en Amazon SNS.

1.    Abra la consola de Lambda.

2.    En el panel de navegación, elija Functions (Funciones).

3.    Elija Create function (Crear función).

4.    Elija Author from scratch (Crear desde cero).

5.    En Function name, ingrese un nombre para su función.

6.    Elija Runtime (Tiempo de ejecución) y, a continuación, elija Python 3.9.

7.    En Architecture (Arquitectura), seleccione x86_64.

8.    Amplíe Change default execution role (Cambiar rol de ejecución predeterminado).

9.    En Execution role (Rol de ejecución), seleccione Create a new role from AWS policy templates (Crear una nuevo rol a partir de plantillas de políticas de AWS).

10.    En Role name (Nombre de rol), ingrese un nombre para el rol.

11.    EnPolicy template (Plantilla de políticas), elija laAmazon SNS publish policy (Política de publicación de Amazon SNS).

12.    Elija Create function (Crear función).

13.    Una vez creada la función, pegue el siguiente código en la sección Code source (Código fuente): 

import json
import boto3

sns = boto3.client('sns')

def lambda_handler(event, context):
    
    #Extract details from JSON event
    detailType= event["detail-type"]
    region = event["region"]
    accountId = event["account"] 
    
    #Security Hub Insight Results
    if (detailType == "Security Hub Insight Results"):
        
        action = event["detail"]["actionDescription"]
        
        message = "Alert: %s in %s for account: %s\n Action description: %s" % (detailType, region,accountId,action)
    
    elif  ("Security Hub Findings" in detailType):
        
        finding = event["detail"]["findings"][0] 
        findingTime = finding["FirstObservedAt"]
        findingType = finding["Types"][0]
        findingDescription = finding["Description"]
        remediation = finding["Remediation"]["Recommendation"]["Text"]
        
        #Security Hub Findings - Custom finding
        if(detailType == "Security Hub Findings - Custom"):
            complianceStatus = finding["Compliance"]["Status"]
            severity = finding["Severity"]["Label"]
            remediationUrl = finding["Remediation"]["Recommendation"]["Url"]
            
            message = "Alert: %s in %s for account: %s\n\nFinding regarding: [%s] %s\n Severity: %s\nDescription: %s\nFirst observed at: %s\n%s: %s" % (detailType, region, accountId, complianceStatus, findingType, 
            severity, findingDescription, findingTime, remediation, remediationUrl)
        
        #Security Hub Findings - Imported finding
        else:
            message = "Alert: %s in %s for account: %s\n\nFinding regarding: %s\nFirst observed at: %s\nRemediation recommendation: %s" % (detailType, region, accountId, findingDescription,findingTime, remediation)
    
    #AWS API Call via CloudTrail finding
    elif (detailType == "AWS API Call via CloudTrail"):
        
        time = event["detail"]["eventTime"]
        eventName = event["detail"]["eventName"]
        requestParameters = event["detail"]["requestParameters"]
        
        message = "Alert: %s in %s for account: %s at time: %s\n\n Event: %s \n Request parameters: %s" % (detailType, region, accountId, time, eventName, requestParameters)
        
        
    #If the event doesn't match any of the above, return the event    
    else:
        message = str(event)
    
    response = sns.publish(
            TopicArn = "arn:aws:sns:eu-west-x:xxxxxxxxxxxx:test",
            Message = message
            )
    
    return {
      'statusCode': 200,
      'body': json.dumps('Success!')
}

Nota: el código anterior personaliza y vuelve a formatear todos los mensajes de alerta de Security Hub. Reemplace TopicArn(“arn:aws:sns:REGION:ACCOUNT_ID:SecurityHubFindings”) por el ARN del tema. Reemplace eu-west-x:xxxxxxxxxxxx por su ID de cuenta. 

14.    Para guardar el código de la función, elija Deploy (Implementar).

Esta función toma los eventos predeterminados de Security Hub y los cambia a un formato más legible. A continuación se muestran mensajes de ejemplo:

Ejemplo 1: resultado de observaciones de Security Hub

Opción predeterminada:

{"version": "0", "id": "ac844908-d14e-05b1-4b7b-836d85110e26", "detail-type": "Security Hub Insight Results", "source": "aws.securityhub", "account": "123456789012", "time": "2019-04-11T21:31:57Z", "region": "us-east-1", "resources": ["arn:aws:securityhub:us-east-1:123456789012:action/custom/slackMessaging"], "detail": {"actionName": "SendToSlack", "actionDescription": "Send Findings to Slack", "insightName": "5. AWS users with the most suspicious activity", "insightArn": "arn:aws:securityhub:::insight/securityhub/default/9", "resultType": "ResourceAwsIamAccessKeyUserName", "insightResults": [{"Admin": 7}, {"DenySlr_UI_User": 1}]}}

Personalizado:

Alert: Security Hub Insight Results in us-east-1 for account: 123456789012
Action description: Send Findings to Slack

Ejemplo 2: hallazgos de Security Hub: acción personalizada

Opción predeterminada:

{ "version": "0", "id": "e215f5c7-a866-e0cd-6d11-fc7ecf97e381", "detail-type": "Security Hub Findings - Custom Action", "source": "aws.securityhub", "account": "123456789012", "time": "2019-04-11T22:06:13Z", "region": "us-east-1", "resources": ["arn:aws:securityhub:us-east-1:123456789012:action/custom/slackMessaging"], "detail": { "actionName": "SendToSlack", "actionDescription": "Send Findings to Slack", "findings": [{ "SchemaVersion": "2018-10-08", "Id": "arn:aws:securityhub:us-east-1:123456789012:subscription/cis-aws-foundations-benchmark/v/1.2.0/1.12/finding/17932c44-6d58-4b3c", "ProductArn": "arn:aws:securityhub:us-east-1::product/aws/securityhub", "GeneratorId": "arn:aws:securityhub:::ruleset/cis-aws-foundations-benchmark/v/1.2.0/rule/1.12", "AwsAccountId": "123456789012", "Types": ["Software and Configuration Checks/Industry and Regulatory Standards/CIS AWS Foundations Benchmark"], "FirstObservedAt": "2018-12-02T05:06:34.874Z", "LastObservedAt": "2019-04-11T18:07:10.995Z", "CreatedAt": "2018-12-02T05:06:34.874Z", "UpdatedAt": "2019-04-11T18:26:20.631Z", "Severity": { "Product": 0, "Normalized": 0 }, "Title": "1.12 Ensure no root account access key exists", "Description": "The root account is the most privileged user in an AWS account...", "Remediation": { "Recommendation": { "Text": "For directions on how to fix this issue, please consult the AWS Security Hub CIS documentation.", "Url": "https://docs.aws.amazon.com/securityhub/latest/userguide/securityhub-standards.html#securityhub-standards-checks-1.12" } }, "ProductFields": { "StandardsGuideArn": "arn:aws:securityhub:::ruleset/cis-aws-foundations-benchmark/v/1.2.0", "StandardsGuideSubscriptionArn": "arn:aws:securityhub:us-east-1:123456789012:subscription/cis-aws-foundations-benchmark/v/1.2.0", "RuleId": "1.12", "RecommendationUrl": "https://docs.aws.amazon.com/securityhub/latest/userguide/securityhub-standards.html#securityhub-standards-checks-1.12", "RecordState": "ACTIVE", "aws/securityhub/FindingId": "arn:aws:securityhub:us-east-1::product/aws/securityhub/arn:aws:securityhub:us-east-1:123456789012:subscription/cis-aws-foundations-benchmark/v/1.2.0/1.12/finding/17932c44-6d58-4b3c", "aws/securityhub/SeverityLabel": "INFORMATIONAL", "aws/securityhub/ProductName": "Security Hub", "aws/securityhub/CompanyName": "AWS" }, "Resources": [{ "Type": "AwsAccount", "Id": "AWS::::Account:123456789012", "Partition": "aws", "Region": "us-east-1" }], "Compliance": { "Status": "PASSED" }, "RecordState": "ACTIVE", "WorkflowState": "NEW" }, { "SchemaVersion": "2018-10-08", "Id": "arn:aws:securityhub:us-east-1:123456789012:subscription/cis-aws-foundations-benchmark/v/1.2.0/2.8/finding/5d6b42d8-122b-4cdf-8498-e045752e170c", "ProductArn": "arn:aws:securityhub:us-east-1::product/aws/securityhub", "GeneratorId": "arn:aws:securityhub:::ruleset/cis-aws-foundations-benchmark/v/1.2.0/rule/2.8", "AwsAccountId": "123456789012", "Types": ["Software and Configuration Checks/Industry and Regulatory Standards/CIS AWS Foundations Benchmark"], "FirstObservedAt": "2019-01-05T05:21:44.990Z", "LastObservedAt": "2019-04-11T18:26:12.510Z", "CreatedAt": "2019-01-05T05:21:44.990Z", "UpdatedAt": "2019-04-11T18:26:12.510Z", "Severity": { "Product": 0, "Normalized": 0 }, "Title": "2.8 Ensure rotation for customer created CMKs is enabled", "Description": "AWS Key Management Service (KMS) allows customers to rotate the backing key...", "Remediation": { "Recommendation": { "Text": "For directions on how to fix this issue, please consult the AWS Security Hub CIS documentation.", "Url": "https://docs.aws.amazon.com/securityhub/latest/userguide/securityhub-standards.html#securityhub-standards-checks-2.8" } }, "ProductFields": { "StandardsGuideArn": "arn:aws:securityhub:::ruleset/cis-aws-foundations-benchmark/v/1.2.0", "StandardsGuideSubscriptionArn": "arn:aws:securityhub:us-east-1:123456789012:subscription/cis-aws-foundations-benchmark/v/1.2.0", "RuleId": "2.8", "RecommendationUrl": "https://docs.aws.amazon.com/securityhub/latest/userguide/securityhub-standards.html#securityhub-standards-checks-2.8", "RecordState": "ACTIVE", "aws/securityhub/FindingId": "arn:aws:securityhub:us-east-1::product/aws/securityhub/arn:aws:securityhub:us-east-1:123456789012:subscription/cis-aws-foundations-benchmark/v/1.2.0/2.8/finding/5d6b42d8-122b-4cdf-8498-e045752e170c", "aws/securityhub/SeverityLabel": "INFORMATIONAL", "aws/securityhub/ProductName": "Security Hub", "aws/securityhub/CompanyName": "AWS" }, "Resources": [{ "Type": "AwsAccount", "Id": "AWS::::Account:123456789012", "Partition": "aws", "Region": "us-east-1" }], "Compliance": { "Status": "PASSED" }, "RecordState": "ACTIVE", "WorkflowState": "NEW" }] } }

Personalizado:

Alert: Security Hub Findings - Custom Action in us-east-1 for account: 123456789012

Finding regarding: The root account is the most privileged user in an AWS account...
First observed at: 2018-12-02T05:06:34.874Z
Remediation recommendation: For directions on how to fix this issue, please consult the AWS Security Hub CIS documentation.

Ejemplo 3: resultados de Security Hub: importado

Opción predeterminada:

{ "version": "0", "id": "8e5622f9-d81c-4d81-612a-9319e7ee2506", "detail-type": "Security Hub Findings - Imported", "source": "aws.securityhub", "account": "123456789012", "time": "2019-04-11T21:52:17Z", "region": "us-west-2", "resources": ["arn:aws:securityhub:us-west-2::product/aws/macie/arn:aws:macie:us-west-2:123456789012:integtest/trigger/6294d71b927c41cbab915159a8f326a3/alert/f2893b211841"], "detail": { "findings": [{ "SchemaVersion": "2018-10-08", "Id": "arn:aws:macie:us-west-2:123456789012:integtest/trigger/6214d71b927c41cbab015159a8f316a3/alert/f2893b211841467198cc1201e9031ee4", "ProductArn": "arn:aws:securityhub:us-west-2::product/aws/macie", "GeneratorId": "arn:aws:macie:us-west-2:123456789012:integtest/trigger/6214d71b927c41cbab015159a8f316a3", "AwsAccountId": "123456789012", "Types": ["Sensitive Data Identifications/Passwords/Google Suite Two-factor backup codes in S3"], "FirstObservedAt": "2019-04-11T21:52:15.900Z", "LastObservedAt": "2019-04-11T21:52:15.900Z", "CreatedAt": "2019-04-11T21:52:15.900Z", "UpdatedAt": "2019-04-11T21:52:15.900Z", "Severity": { "Product": 6, "Normalized": 15 }, "Confidence": 5, "Title": "Google Suite Two-Factor Backup Codes uploaded to S3", "Description": "Google Suite two-factor backup codes uploaded to S3....", "Remediation": { "Recommendation": { "Text": "v2 Release" } }, "ProductFields": { "rule-arn": "arn:aws:macie:us-west-2:123456789012:trigger/6214d71b927c41cbab015159a8f316a3", "tags:0": "DATA_COMPLIANCE", "tags:1": "BASIC_ALERT", "themes:0/theme": "google_two_factor_backup", "themes:0/count": "1", "dlpRisk:0/risk": "8", "dlpRisk:0/count": "1", "owner:0/name": "vchin", "owner:0/count": "1", "aws/securityhub/FindingId": "arn:aws:securityhub:us-west-2::product/aws/macie/arn:aws:macie:us-west-2:123456789012:integtest/trigger/6214d71b927c41cbab015159a8f316a3/alert/f2893b211841467198cc1201e9031ee4", "aws/securityhub/SeverityLabel": "LOW", "aws/securityhub/ProductName": "Macie", "aws/securityhub/CompanyName": "Amazon" }, "Resources": [{ "Type": "AwsS3Bucket", "Id": "arn:aws:s3:::test-bucket-12", "Partition": "aws", "Region": "us-west-2" }], "RecordState": "ACTIVE", "WorkflowState": "NEW" }] } }

Personalizado:

Alert: Security Hub Findings - Imported in us-west-2 for account: 123456789012

Finding regarding: Google Suite two-factor backup codes uploaded to S3....
First observed at: 2019-04-11T21:52:15.900Z
Remediation recommendation: v2 Release

Ejemplo 4: llamada a la API de AWS a través de CloudTrail

Opción predeterminada:

{"version": "0", "id": "b34c4525-95f0-8dd1-cd9e-9fc5be10039e", "detail-type": "AWS API Call via CloudTrail", "source": "aws.securityhub", "account": "123456789012", "time": "2021-12-10T10:47:54Z", "region": "eu-west-1", "resources": [], "detail": {"eventVersion": "1.08", "userIdentity": {"type": "AssumedRole", "principalId": "AROATGMYP4FKHTE5RKJC3", "arn": "arn:aws:sts::123456789012", "accountId": "123456789012", "accessKeyId": "ASIATGMYXXFKNHWOYQF7", "sessionContext": {"sessionIssuer": {"type": "Role", "principalId": "AROATGMYP4FKHX5RKJC3", "arn": "arn:aws:iam::123456789012:role/Admin", "accountId": "123456789012", "userName": "Admin"}, "webIdFederationData": {}, "attributes": {"creationDate": "2021-12-10T10:08:16Z", "mfaAuthenticated": "false"}}}, "eventTime": "2021-12-10T10:47:54Z", "eventSource": "securityhub.amazonaws.com", "eventName": "BatchUpdateFindings", "awsRegion": "eu-west-1", "sourceIPAddress": "54.240.197.20", "userAgent": "aws-internal/3 aws-sdk-java/1.12.112 Linux/5.4.156-94.273.amzn2int.x86_64 OpenJDK_64-Bit_Server_VM/25.312-b07 java/1.8.0_312 vendor/Oracle_Corporation cfg/retry-mode/standard", "requestParameters": {"Workflow": {"Status": "NEW"}, "FindingIdentifiers": [{"Id": "arn:aws:securityhub:eu-west-1:123456789012:subscription/cis-aws-foundations-benchmark/v/1.2.0/2.5/finding/2fd7f0dd-1088-44c5-bbe1-9c8a0ddce035", "ProductArn": "arn:aws:securityhub:eu-west-1::product/aws/securityhub"}]}, "responseElements": {"UnprocessedFindings": [], "ProcessedFindings": [{"Id": "arn:aws:securityhub:eu-west-1:123456789012:subscription/cis-aws-foundations-benchmark/v/1.2.0/2.5/finding/2fd7f0dd-1088-44c5-bbe1-9c8a0ddce035", "ProductArn": "arn:aws:securityhub:eu-west-1::product/aws/securityhub"}]}, "requestID": "fd52e76e-282f-47c7-a7bc-b9a1e1ca2cdd", "eventID": "433b8e9c-cf08-4909-adf7-ea0c548459ad", "readOnly": "False", "eventType": "AwsApiCall", "managementEvent": "True", "recipientAccountId": "123456789012", "eventCategory": "Management"}}

Personalizado:

Alert: AWS API Call via CloudTrail in eu-west-1 for account: 123456789012 at time: 2021-12-10T10:47:32Z

Event: BatchUpdateFindings
Request parameters: {'Workflow': {'Status': 'NOTIFIED'}, 'FindingIdentifiers': [{'Id': 'arn:aws:securityhub:eu-west-x:xxxxxxxxxxxx:subscription/cis-aws-foundations-benchmark/v/1.2.0/2.5/finding/2fd7f0dd-1088-44c5-bbe1-9c8a0ddce035', 'ProductArn': 'arn:aws:securityhub:eu-west-1::product/aws/securityhub'}]}

Nota: puede editar el mensaje para cada tipo de búsqueda de seguridad para que sea más adecuado para su caso de uso.

Crear y configurar la regla de EventBridge

1.    Abra la consola de EventBridge.

2.    Seleccione Create rule (Crear regla).

3.    Ingrese un nombre para su regla. Si lo desea, puede ingresar una descripción.

4.    En Define pattern (Definir patrón), seleccione Event pattern (Patrón de eventos).

5.    En Event matching pattern (Patrón de coincidencia de eventos), seleccione Pre-defined pattern by service (Patrón predefinido por servicio).

6.    En Service provider (Proveedor de servicios), seleccione AWS.

7.    En Service name (Nombre del servicio), seleccione Security Hub.

8.    En Event type (Tipo de evento), seleccioneAll Events (Todos los eventos).

Nota: también puede configurar alertas para eventos específicos en lugar de para todos los eventos. La función Lambda está configurada para reformatear todos los eventos en un formato más legible.

9.    En la sección Select event bus (Seleccionar bus de eventos), seleccione AWS default event bus (bus de eventos predeterminado de AWS).

10.    En Select targets (Seleccionar destinos), elija Lambda target (Destino Lambda) en el menú Target (Destino).

11.    Seleccione la función Lambda creada anteriormente.

Recibir una notificación personalizada

Cuando se produce cualquiera de los eventos configurados, recibirá una notificación personalizada mediante correo electrónico de no-reply@sns.amazonaws.com.