[New Rule] AWS SES Full Access Policy Attached to IAM Entity

[bryans3c]

Pull Request

Issue link(s):

• https://github.com/elastic/ia-trade-team/issues/1066

Summary - What I changed

Added a query rule that fires when the AWS managed policy AmazonSESFullAccess is attached to any IAM user, role, or group via AttachUserPolicy, AttachRolePolicy, or AttachGroupPolicy.

Why it matters

Threat actors who compromise an AWS account frequently establish phishing infrastructure by attaching AmazonSESFullAccess to a new or existing IAM entity, enabling bulk email delivery from the victim organization's verified sending domains. AmazonSESFullAccess grants unrestricted access to send email, manage identities, manage suppression lists, and configure account-level settings — making it the broadest possible SES grant. Attaching this specific managed policy is the simplest one-step path to full SES capability, and its use for legitimate automation is uncommon given that scoped SES policies are the recommended practice.

• https://docs.aws.amazon.com/ses/latest/dg/control-user-access.html

How To Test

Query to verify in our TRaDE stack:

data_stream.dataset: "aws.cloudtrail"
    and event.provider: "iam.amazonaws.com"
    and event.action: ("AttachUserPolicy" or "AttachRolePolicy" or "AttachGroupPolicy")
    and event.outcome: "success"
    and aws.cloudtrail.request_parameters: *AmazonSESFullAccess*

Checklist

• Added a label for the type of pr: Rule: New
• 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?

[Copilot]

Pull request overview

Adds a new AWS CloudTrail query rule to detect attachment of the AWS-managed AmazonSESFullAccess policy to IAM users, roles, or groups—behavior commonly associated with establishing phishing infrastructure via SES abuse.

Changes:

• Introduces a new kuery rule matching successful AttachUserPolicy / AttachRolePolicy / AttachGroupPolicy events where request parameters contain AmazonSESFullAccess.
• Adds an investigation guide covering triage steps, false positives, and response/remediation actions.
• Defines initial ATT&CK mappings, setup guidance, and investigation fields for alert context.

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[github-actions]

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.
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Testing and Validation

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

[imays11]

Since this is a managed policy with a consistent/predictable name couldn't you just avoid the double wildcard usage here by using the full flattened request_parameters.policyArn field or related.entity field to query "arn:aws:iam::aws:policy/AmazonSESFullAccess"

[terrancedejesus]

Suggested change

	to an unexpected IAM entity — particularly a newly created user or a role not previously associated
	with email operations — is a documented technique used by threat actors to establish phishing
	to an unexpected IAM entity, particularly a newly created user or a role not previously associated
	with email operations, is a documented technique used by threat actors to establish phishing

[terrancedejesus]

Suggested change

interval = "5m"

default

[terrancedejesus]

Suggested change

	risk_score = 73
	risk_score = 47

Not inherently malicious, just poor security posture.

[terrancedejesus]

Suggested change

	severity = "high"
	severity = "medium"

[terrancedejesus]

Suggested change

	and aws.cloudtrail.request_parameters: *AmazonSESFullAccess*
	and aws.cloudtrail.flattened.request_parameters.policyArn: "arn:aws:iam::aws:policy/AmazonSESFullAccess"

to @imays11's point

[terrancedejesus]

LGTM. Agreed on medium, attaching SESFullAccess is poor posture more than it is inherently malicious. Also +1 on matching the exact policy ARN via flattened.request_parameters.