splunk-security_content/docs/_posts/2021-07-19-aws_createaccesskey.md

title, excerpt, categories, last_modified_at, toc, toc_label, tags

title	excerpt	categories	last_modified_at	toc	toc_label	tags
AWS CreateAccessKey	Cloud Account , Create Account	Cloud	2021-07-19	true		Cloud Account Create Account Persistence Persistence Splunk Enterprise Splunk Enterprise Security Splunk Cloud

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Description

This search looks for AWS CloudTrail events where a user A who has already permission to create access keys, makes an API call to create access keys for another user B. Attackers have been know to use this technique for Privilege Escalation in case new victim(user B) has more permissions than old victim(user B)

• Type: Hunting
• Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
• Datamodel:
• Last Updated: 2021-07-19
• Author: Bhavin Patel, Splunk
• ID: 2a9b80d3-6340-4345-11ad-212bf3d0d111

ATT&CK

ID	Technique	Tactic
T1136.003	Cloud Account	Persistence

| T1136 | Create Account | Persistence |

Search

`cloudtrail` eventName = CreateAccessKey userAgent !=console.amazonaws.com errorCode = success
| search userIdentity.userName!=requestParameters.userName  
|  stats count min(_time) as firstTime max(_time) as lastTime  by requestParameters.userName src eventName eventSource aws_account_id errorCode userAgent eventID awsRegion userIdentity.principalId user_arn 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)`
|`aws_createaccesskey_filter`

Macros

The SPL above uses the following Macros:

• cloudtrail
• security_content_ctime

Note that aws_createaccesskey_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Required field

• _time
• eventName
• userAgent
• errorCode
• requestParameters.userName

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 keys for another user.

Associated Analytic story

• AWS IAM Privilege Escalation

Kill Chain Phase

• Actions on Objectives

RBA

Risk Score	Impact	Confidence	Message
63.0	70	90	User user_arn is attempting to create access keys for requestParameters.userName from this IP src

Reference

• https://labs.bishopfox.com/tech-blog/privilege-escalation-in-aws
• https://rhinosecuritylabs.com/aws/aws-privilege-escalation-methods-mitigation-part-2/

Test Dataset

Replay any dataset to Splunk Enterprise by using our replay.py tool or the UI. Alternatively you can replay a dataset into a Splunk Attack Range

• https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1078/aws_createaccesskey/aws_cloudtrail_events.json

source | version: 2