[New Rule] Adding Coverage for AWS IAM Customer-Managed Policy Attached to Role by Rare User

[terrancedejesus]

Pull Request

Issue link(s):

• https://github.com/elastic/ia-trade-team/issues/456
• https://github.com/elastic/ia-trade-team/issues/272

Summary - What I changed

Adding detection coverage for AWS IAM Customer-Managed Policy Attached to Role by Rare User.
Adds an ES|QL hunting query for similar activity --> AWS IAM Customer-Managed Policy Attachment to Existing Roles.

Detects when an AWS Identity and Access Management (IAM) customer-managed policy is attached to a role by an unusual or unauthorized user. Customer-managed policies are policies created and controlled within an AWS account, granting specific permissions to roles or users when attached. This rule identifies potential privilege escalation by flagging
cases where a customer-managed policy is attached to a role by an unexpected actor, which could signal unauthorized
access or misuse. Attackers may attach policies to roles to expand permissions and elevate their privileges within the AWS environment.

This is a New Terms rule that uses the aws.cloudtrail.user_identity.arn and aws.cloudtrail.flattened.request_parameters.roleName fields to check if the combination of the actor ARN and target role name has not been seen in the last 14 days.

How To Test

Checklist

• Added a label for the type of pr: bug, enhancement, schema, Rule: New, Rule: Deprecation, Rule: Tuning, Hunt: New, or Hunt: Tuning so guidelines can be generated
• Added the meta:rapid-merge label if planning to merge within 24 hours
• Secret and sensitive material has been managed correctly
• Automated testing was updated or added to match the most common scenarios
• Documentation and comments were added for features that require explanation

Contributor checklist

• Have you signed the contributor license agreement?
• Have you followed the contributor guidelines?

[protectionsmachine]

Enhancement - Guidelines

These guidelines serve as a reminder set of considerations when addressing adding a new schema feature to the code.

Documentation and Context

• Describe the feature enhancement in detail (alternative solutions, description of the solution, etc.) if not already documented in an issue.
• Include additional context or screenshots.
• Ensure the enhancement includes necessary updates to the documentation and versioning.

Code Standards and Practices

• Code follows established design patterns within the repo and avoids duplication.
• Code changes do not introduce new warnings or errors.
• Variables and functions are well-named and descriptive.
• Any unnecessary / commented-out code is removed.
• Ensure that the code is modular and reusable where applicable.
• Check for proper exception handling and messaging.

Testing

• New unit tests have been added to cover the enhancement.
• Existing unit tests have been updated to reflect the changes.
• Provide evidence of testing and validating the enhancement (e.g., test logs, screenshots).
• Validate that any rules affected by the enhancement are correctly updated.
• Ensure that performance is not negatively impacted by the changes.
• Verify that any release artifacts are properly generated and tested.

Additional Schema Related Checks

• Ensure that the enhancement does not break existing functionality. (e.g., run make test-cli)
• Review the enhancement with a peer or team member for additional insights.
• Verify that the enhancement works across all relevant environments (e.g., different OS versions).
• Confirm that all dependencies are up-to-date and compatible with the changes.
• Link to the relevant Kibana PR or issue provided
• Exported detection rule(s) from Kibana to showcase the feature(s)
• Converted the exported ndjson file(s) to toml in the detection-rules repo
• Re-exported the toml rule(s) to ndjson and re-imported into Kibana
• Updated necessary unit tests to accommodate the feature
• Applied min_compat restrictions to limit the feature to a specified minimum stack version
• Executed all unit tests locally with a test toml rule to confirm passing
• Included Kibana PR implementer as an optional reviewer for insights on the feature
• Implemented requisite downgrade functionality
• Cross-referenced the feature with product documentation for consistency
• Incorporated a comprehensive test rule in unit tests for full schema coverage
• Conducted system testing, including fleet, import, and create APIs (e.g., run make test-remote-cli)
• Confirm that the proper version label is applied to the PR patch, minor, major.