Enabling Malware Protection for S3 for your bucket

This section provides detailed steps on how to enable Malware Protection for S3 for a bucket in your own account. Before following the steps in this section, you will need an IAM role with permissions that help GuardDuty take action on your behalf. For more information, see Prerequisite - Create or update IAM role policy.

You can choose a preferred access method to enable Malware Protection for S3 for your buckets - GuardDuty console or API/AWS CLI.

Enabling Malware Protection for S3 by using GuardDuty console

The following sections provide a step-by-step walkthrough as you will experience in the GuardDuty console.

To enable Malware Protection for S3 by using GuardDuty console

Enter S3 bucket details

Use the following steps to provide the Amazon S3 bucket details:

1. Sign in to the AWS Management Console and open the GuardDuty console at https://console.aws.amazon.com/guardduty/.

2. By using the AWS Region selector in the upper-right corner of the page, select the Region where you want to enable Malware Protection for S3.

3. In the navigation pane, choose Malware Protection for S3.

4. In the Protected buckets section, choose Enable to enable Malware Protection for S3 for an S3 bucket that belongs to your own AWS account.

5. Under Enter S3 bucket details, enter the Amazon S3 bucket name. Alternatively, choose Browse S3 to select an S3 bucket.

   The AWS Region of the S3 bucket and the AWS account where you enable Malware Protection for S3 must be the same. For example, if your account belongs to the us-east-1 Region, then your Amazon S3 bucket Region must also be us-east-1.

6. Under Prefix, you can select either All the objects in the S3 bucket or Objects beginning with a specific prefix.

   • Select All the objects in the S3 bucket when you want GuardDuty can scan all the newly uploaded objects in the selected bucket.

   • Select Objects beginning with a specific prefix when you want scan the newly uploaded objects that belong to a specific prefix. This option helps you focus the scope of the malware scan on the selected object prefixes only. For more information about using prefixes, see Organizing objects in Amazon S3 console by using folders in the Amazon S3 User Guide.

     Choose Add prefix and enter prefix. You can add up to five prefixes.

Enable tagging for scanned objects

This is an optional step. When you enable the tagging option before an object gets uploaded to your bucket, then after completing the scan, GuardDuty will add a predefined tag with key as GuardDutyMalwareScanStatus and the value as the scan result. To use Malware Protection for S3 optimally, we recommend to enable the option to add tag to the S3 objects after the scan ends. Standard S3 Object Tagging cost applies. For more information, see Pricing and usage cost for Malware Protection for S3.

Why should you enable tagging?

• Enabling tagging is one of the ways to know about the malware scan result. For information about an S3 malware scan result, see Monitoring S3 object scans in Malware Protection for S3.

• Set up tag-based access control (TBAC) policy on your S3 bucket that contains the potentially malicious object. For information about considerations and how to implement tag-based access control (TBAC), see Using tag-based access control (TBAC) with Malware Protection for S3.

Considerations for GuardDuty to add a tag to your S3 object:

• By default, you can associate up to 10 tags with an object. For more information, see Categorizing your storage using tags in the Amazon S3 User Guide.

  If all 10 tags are already in use, GuardDuty can't add the predefined tag to the scanned object. GuardDuty also publishes the scan result to your default EventBridge event bus. For more information, see Monitoring S3 object scans with Amazon EventBridge.

• When the selected IAM role does't include the permission for GuardDuty to tag the S3 object, then even with tagging enabled for your protected bucket, GuardDuty will be unable to add tag to this scanned S3 object. For more information about the required IAM role permission for tagging, see Prerequisite - Create or update IAM role policy.

  GuardDuty also publishes the scan result to your default EventBridge event bus. For more information, see Monitoring S3 object scans with Amazon EventBridge.

To select an option under Tag scanned objects

• When you want GuardDuty to add tags to your scanned S3 objects, select Tag objects.

• When you don't want GuardDuty to add tags to your scanned S3 objects, select Do not tag objects.

Permissions

Use the following steps to choose an IAM role that has the necessary permissions to perform malware scan actions on your behalf. These actions may include scanning the newly uploaded S3 objects and (optionally) adding tags to those objects.

To choose an IAM role name

1. If you have already performed the steps under Prerequisite - Create or update IAM role policy, then do the following:

   1. Under the Permissions section, for the IAM role name, choose an IAM role name that includes the necessary permissions.

2. If you haven't already performed the steps under Prerequisite - Create or update IAM role policy, then do the following:

   1. Choose View permissions.

   2. Under Permission details, choose the Policy tab. This shows a template of the required IAM permissions.

      Copy this template and then choose Close at the end of the Permission details window.

   3. Choose Attach policy that opens the IAM console in a new tab. You can choose to create a new IAM role or update an existing IAM role with the permissions from the copied template.

      This template includes placeholder values that you must replace with the appropriate values associated with your bucket and AWS account.

   4. Go back to the browser tab with the GuardDuty console. Choose View permissions again.

   5. Under Permission details, choose the Trust relationship tab. This shows a template of the trust relationship policy for your IAM role.

      Copy this template and then choose Close at the end of the Permission details window.

   6. Go to the browser tab that has the IAM console open. To your preferred IAM role, add this trust relationship policy.

3. To add tags to your Malware Protection plan ID that gets created for this protected resource, continue with the next section; otherwise, choose Enable at the end of this page to add the S3 bucket as a protected resource.

(Optional) Tag Malware Protection plan ID

This is an optional step that helps you add tags to the Malware Protection plan resource that would get created for your S3 bucket resource.

Each tag has two parts: A tag key and an optional tag value. For more information about tagging and its benefits, see Tagging AWS resources.

To add tags to your Malware Protection plan resource

1. Enter Key and an optional Value for the tag. Both tag key and tag value are case sensitive. For information about names of tag key and tag value, see Tag naming limits and requirements.

2. To add more tags to your Malware Protection plan resource, choose Add new tag and repeat the previous step. You can add up to 50 tags to each resource.

3. Choose Enable.

Enabling Malware Protection for S3 by using API/CLI

This section includes the steps for when you want to enable Malware Protection for S3 programmatically in your AWS environment. This requires the IAM role Amazon Resource Name (ARN) that you created in this step - Prerequisite - Create or update IAM role policy.

To enable Malware Protection for S3 programmatically by using API/CLI

• By using the API

  Run the CreateMalwareProtectionPlan to enable Malware Protection for S3 for a bucket that belongs to your own account.

• By using AWS CLI

  Depending on how you want to enable Malware Protection for S3, the following list provides AWS CLI example commands for specific use case. When you run these commands, replace the placeholder examples shown in red, with the values that are appropriate for your account.

  AWS CLI example commands

  • Use the following AWS CLI command to enable Malware Protection for S3 for a bucket with no tagging for scanned S3 objects:

    aws guardduty create-malware-protection-plan --role "arn:aws:iam::111122223333:role/role-name" --protected-resource "S3Bucket"={"BucketName"="amzn-s3-demo-bucket1"}

  • Use the following AWS CLI command to enable Malware Protection for S3 for a bucket with specific object prefixes and no tagging for scanned S3 objects:

    aws guardduty create-malware-protection-plan --role "arn:aws:iam::111122223333:role/role-name" --protected-resource '{"S3Bucket":{"BucketName":"amzn-s3-demo-bucket1", "ObjectPrefixes": ["Object1","Object1"]}}'

  • Use the following AWS CLI command to enable Malware Protection for S3 for a bucket with scanned S3 object tagging enabled:

    aws guardduty create-malware-protection-plan --role "arn:aws:iam::111122223333:role/role-name" --protected-resource "S3Bucket"={"BucketName"="amzn-s3-demo-bucket1"} --actions "Tagging"={"Status"="ENABLED"}

  After you run these commands successfully, a unique Malware Protection plan ID will get generated. To perform actions such as updating or disabling the protection plan for your bucket, you will need this Malware Protection plan ID.