AWS IAM Inline Policy Added to a Group

Last updated 9 days ago on 2026-06-18

Created 9 days ago on 2026-06-18

About

Identifies an inline policy added to an IAM group via PutGroupPolicy. An inline policy attached to a group grants its permissions to every current and future member of that group. Adversaries can abuse this to escalate privileges (grant elevated permissions to a group they belong to, or will add themselves to) and to establish persistence through a durable, membership-based grant that is easy to overlook. Group inline policies are uncommon compared to managed-policy attachments, so their creation by an unexpected principal warrants review.

Tags

Domain: CloudDomain: IdentityData Source: AWSData Source: Amazon Web ServicesData Source: AWS IAMUse Case: Threat DetectionTactic: Privilege EscalationTactic: PersistenceLanguage: kuery

Severity

medium

Risk Score

MITRE ATT&CK™

Privilege Escalation (TA0004)(external, opens in a new tab or window)

↳ Account Manipulation (T1098)(external, opens in a new tab or window)

Persistence (TA0003)(external, opens in a new tab or window)

↳ Account Manipulation (T1098)(external, opens in a new tab or window)

False Positive Examples

Identity and platform teams and infrastructure-as-code pipelines occasionally manage group inline policies as part of normal access governance. Verify the principal in `aws.cloudtrail.user_identity.arn`, the targeted group, and the policy document against approved change records. Known administration roles and deployment automation can be excluded after validation.

License

Elastic License v2(external, opens in a new tab or window)

Definition

Rule Type: Query (Kibana Query Language)
Integration Pack: Prebuilt Security Detection Rules
Index Patterns: logs-aws.cloudtrail-*
Related Integrations: aws(external, opens in a new tab or window)
Query

✄𐘗text code block:
✄𐘗data_stream.dataset: "aws.cloudtrail"
    and event.provider: "iam.amazonaws.com"
    and event.action: "PutGroupPolicy"
    and event.outcome: "success"
    and not aws.cloudtrail.user_identity.type: "AWSService"
    and not user_agent.original: (*terraform* or *pulumi* or *ansible*)
    and not aws.cloudtrail.user_identity.arn: (*terraform* or *pulumi* or *ansible*)
    and not source.as.organization.name: (Amazon* or AMAZON* or Google*)
    and not source.address: ("cloudformation.amazonaws.com" or "servicecatalog.amazonaws.com")

Install detection rules in Elastic Security

Detect AWS IAM Inline Policy Added to a Group in the Elastic Security detection engine by installing this rule into your Elastic Stack.

To setup this rule, check out the installation guide for Prebuilt Security Detection Rules(external, opens in a new tab or window).