ASL AWS Create Policy Version to allow all resources

Original Source: [splunk source]
Name:ASL AWS Create Policy Version to allow all resources
id:22cc7a62-3884-48c4-82da-592b8199b72f
version:1
date:2024-12-12
author:Patrick Bareiss, 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:
  • -ASL AWS CloudTrail
search:`amazon_security_lake` api.operation=CreatePolicy
| spath input=api.request.data
| spath input=policyDocument
| regex Statement{}.Action="\*"
| regex Statement{}.Resource="\*"
| fillnull
| stats count min(_time) as firstTime max(_time) as lastTime by api.operation actor.user.uid actor.user.account.uid http_request.user_agent src_endpoint.ip cloud.region api.request.data
| rename actor.user.uid as user, src_endpoint.ip as src_ip, cloud.region as region, http_request.user_agent as user_agent
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`|`asl_aws_create_policy_version_to_allow_all_resources_filter`


how_to_implement:The detection is based on Amazon Security Lake events from Amazon Web Services (AWS), which is a centralized data lake that provides security-related data from AWS services. To use this detection, you must ingest CloudTrail logs from Amazon Security Lake into Splunk. To run this search, ensure that you ingest events using the latest version of Splunk Add-on for Amazon Web Services (https://splunkbase.splunk.com/app/1876) or the Federated Analytics App.
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 ("$user$") starthoursago=168 | 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:'$info_min_time$'
latest_offset:'$info_max_time$'
tags:
  analytic_story:
    - 'AWS IAM Privilege Escalation'
  asset_type:AWS Account
  confidence:70
  impact:70
  message:User $user$ created a policy version that allows them to access any resource in their account.
  mitre_attack_id:
    - 'T1078.004'
    - 'T1078'
  observable:
    name:'user'
    type:'User'
    - role:
      - 'Victim'
  product:
    - 'Splunk Enterprise'
    - 'Splunk Enterprise Security'
    - 'Splunk Cloud'
  required_fields:
    - 'api.operation'
    - 'actor.user.account.uid'
    - 'api.request.data'
    - 'actor.user.uid'
    - 'http_request.user_agent'
    - 'src_endpoint.ip'
    - 'src_endpoint.domain'
    - 'cloud.region'
  risk_score:49
  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/asl_ocsf_cloudtrail.json
  sourcetype: aws:asl
  source: aws_asl
manual_test:None

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AWS IAM Privilege Escalation