AWS Create Policy Version to allow all resources

SPLUNK detection rule by Bhavin Patel, Splunk · Apache-2.0

The following analytic identifies the creation of a new AWS IAM policy version that allows access to all resources. It detects this activity by analyzing AWS CloudTrail logs for the CreatePolicyVersion event with a policy document that grants broad permissions. This behavior is significant because it violates the principle of least privilege, potentially exposing the environment to misuse or abuse. If confirmed malicious, an attacker could gain extensive access to AWS resources, leading to unauthorized actions, data exfiltration, or further compromise of the AWS environment.

name: AWS Create Policy Version to allow all resources
id: 2a9b80d3-6340-4345-b5ad-212bf3d0dac4
version: 14
creation_date: '2021-02-22'
modification_date: '2026-05-13'
author: Bhavin Patel, Splunk
status: production
type: TTP
description: The following analytic identifies the creation of a new AWS IAM policy version that allows access to all resources. It detects this activity by analyzing AWS CloudTrail logs for the CreatePolicyVersion event with a policy document that grants broad permissions. This behavior is significant because it violates the principle of least privilege, potentially exposing the environment to misuse or abuse. If confirmed malicious, an attacker could gain extensive access to AWS resources, leading to unauthorized actions, data exfiltration, or further compromise of the AWS environment.
data_source:
    - AWS CloudTrail CreatePolicyVersion
search: |-
    `cloudtrail` eventName=CreatePolicyVersion eventSource = iam.amazonaws.com errorCode = success
      | spath input=requestParameters.policyDocument output=key_policy_statements path=Statement{}
      | mvexpand key_policy_statements
      | spath input=key_policy_statements output=key_policy_action_1 path=Action
      | where key_policy_action_1 = "*"
      | rename user_name as user
      | stats count min(_time) as firstTime max(_time) as lastTime values(key_policy_statements) as policy_added
        BY signature dest user
           user_agent src vendor_account
           vendor_region vendor_product
      | `security_content_ctime(firstTime)`
      | `security_content_ctime(lastTime)`
      | `aws_create_policy_version_to_allow_all_resources_filter`
how_to_implement: You must install splunk AWS add on and Splunk App for AWS. This search works with AWS CloudTrail logs.
known_false_positives: While this search has no known false positives, it is possible that an AWS admin has legitimately created a policy to allow a user to access all resources. That said, AWS strongly advises against granting full control to all AWS resources and you must verify this activity.
references:
    - https://bishopfox.com/blog/privilege-escalation-in-aws
    - https://rhinosecuritylabs.com/aws/aws-privilege-escalation-methods-mitigation-part-2/
drilldown_searches:
    - name: View the detection results for - "$user$"
      search: '%original_detection_search% | search  user = "$user$"'
      earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
    - name: View risk events for the last 7 days for - "$user$"
      search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$user$") | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`'
      earliest_offset: 7d
      latest_offset: "0"
finding:
    title: User $user$ created a policy version that allows them to access any resource in their account.
    entity:
        field: user
        type: user
        score: 50
analytic_story:
    - AWS IAM Privilege Escalation
asset_type: AWS Account
mitre_attack_id:
    - T1078.004
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: cloud
security_domain: network
tests:
    - name: True Positive Test
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1078/aws_create_policy_version/aws_cloudtrail_events.json
          sourcetype: aws:cloudtrail
          source: aws_cloudtrail
      test_type: unit

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