[New Rule] AWS STS AssumeRole with New MFA Device [Rule Tuning] AWS IAM Deactivation of MFA Device

[imays11]

Pull Request

Issue link(s):

• https://github.com/elastic/ia-trade-team/issues/458
• https://github.com/elastic/ia-trade-team/issues/347

Summary - What I changed

This PR creates a new rule to identify when a user has assumed a role using a new MFA device. Users can assume a role to obtain temporary credentials and access AWS resources using the AssumeRole API of AWS Security Token Service (STS).
While a new MFA device is not always indicative of malicious behavior it should be verified as adversaries can use this technique for persistence and privilege escalation.

This PR also adds the proper MITRE technique to existing rule "AWS IAM Deactivation of MFA Device"

How To Test

Screenshot of working query

You can use the Cloudgoat Scenario: iam_privesc_by_key_rotation to test this rule. Part of the attack chain is for a user to add a new MFA device to a compromised user before assuming a role for privilege escalation.

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
• Secret and sensitive material has been managed correctly

[protectionsmachine]

Rule: New - Guidelines

These guidelines serve as a reminder set of considerations when proposing a new rule.

Documentation and Context

• Detailed description of the rule.
• List any new fields required in ECS/data sources.
• Link related issues or PRs.
• Include references.

Rule Metadata Checks

• creation_date matches the date of creation PR initially merged.
• min_stack_version should support the widest stack versions.
• name and description should be descriptive and not include typos.
• query should be inclusive, not overly exclusive, considering performance for diverse environments. Non ecs fields should be added to non-ecs-schema.json if not available in an integration.
• min_stack_comments and min_stack_version should be included if the rule is only compatible starting from a specific stack version.
• index pattern should be neither too specific nor too vague, ensuring it accurately matches the relevant data stream (e.g., use logs-endpoint.process-* for process data).
• integration should align with the index. If the integration is newly introduced, ensure the manifest, schemas, and new_rule.yaml template are updated.
• setup should include the necessary steps to configure the integration.
• note should include any additional information (e.g. Triage and analysis investigation guides, timeline templates).
• tags should be relevant to the threat and align/added to the EXPECTED_RULE_TAGS in the definitions.py file.
• threat, techniques, and subtechniques should map to ATT&CK always if possible.

New BBR Rules

• building_block_type should be included if the rule is a building block and the rule should be located in the rules_building_block folder.
• bypass_bbr_timing should be included if adding custom lookback timing to the rule.

Testing and Validation

• Provide evidence of testing and detecting the expected threat.
• Check for existence of coverage to prevent duplication.

[protectionsmachine]

Rule: New - Guidelines

These guidelines serve as a reminder set of considerations when proposing a new rule.

Documentation and Context

• Detailed description of the rule.
• List any new fields required in ECS/data sources.
• Link related issues or PRs.
• Include references.

Rule Metadata Checks

• creation_date matches the date of creation PR initially merged.
• min_stack_version should support the widest stack versions.
• name and description should be descriptive and not include typos.
• query should be inclusive, not overly exclusive, considering performance for diverse environments. Non ecs fields should be added to non-ecs-schema.json if not available in an integration.
• min_stack_comments and min_stack_version should be included if the rule is only compatible starting from a specific stack version.
• index pattern should be neither too specific nor too vague, ensuring it accurately matches the relevant data stream (e.g., use logs-endpoint.process-* for process data).
• integration should align with the index. If the integration is newly introduced, ensure the manifest, schemas, and new_rule.yaml template are updated.
• setup should include the necessary steps to configure the integration.
• note should include any additional information (e.g. Triage and analysis investigation guides, timeline templates).
• tags should be relevant to the threat and align/added to the EXPECTED_RULE_TAGS in the definitions.py file.
• threat, techniques, and subtechniques should map to ATT&CK always if possible.

New BBR Rules

• building_block_type should be included if the rule is a building block and the rule should be located in the rules_building_block folder.
• bypass_bbr_timing should be included if adding custom lookback timing to the rule.

Testing and Validation

• Provide evidence of testing and detecting the expected threat.
• Check for existence of coverage to prevent duplication.

[Aegrah]

Why do we use a wildcard in an event.action statement?

[imays11]

@Aegrah to capture AssumeRole, AssumeRoleWithSAML and AssumeRoleWithWebIdentity. I could just explicitly call these out and change to an OR statement if that would be better

[Aegrah]

Then I would suggest adding event.action:(AssumeRole or AssumeRoleWithSAML or AssumeRoleWithWebIdentity) to enhance rule performance.