Change Default Policy Version (aws)

Platform	Author	Last Update
aws	Nick Jones	2024-12-02

An attacker may attempt to change the default policy version of a policy to one that includes a different set of permissions

MITRE IDs

T1098

Required Permissions

iam:SetDefaultPolicyVersion

Required Parameters

Name	Type	Description	Example Value
policy_arn	str	ARN of the policy to create a new version for	arn:aws:iam::123456789012:policy/test
policy_version	str	Version of the policy to set as default	v2

Attacker Action

aws iam set-default-policy-version –policy-arn policy_arn –version-id policy_version

Detection Case

ELK query

When logs are ingested into ELK, the following Lucene query can be used to identify relevant events.

eventName:SetDefaultPolicyVersion AND eventSource:iam.amazonaws.com

Sigma Definition

---
title: Change default policy version
id: 089c1b6a-1d77-4071-aac7-c91488ad88d5
status: experimental
author: Nick Jones
date: 2024-12-02
description: An attacker may attempt to change the default policy version of a policy to one that includes a different set of permissions
logsource:
  service: cloudtrail
detection:
  selection_source:
    - eventSource: "iam.amazonaws.com"
  events:
    - eventName: "SetDefaultPolicyVersion"
  condition: selection_source and events
level: low
tags:
  - attack.T1098


falsepositives:
  - Developers making legitimate changes to the environment. Verify whether the user identity, user agent, and/or hostname should be making changes in your environment.