:warning: THIS IS A EXPERIMENTAL DETECTION

This detection has been marked experimental by the Splunk Threat Research team. This means we have not been able to test, simulate, or build datasets for this detection. Use at your own risk. This analytic is NOT supported.

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Description

The following analytic detects unauthenticated requests made against the Kubernetes' Pods API through proactive monitoring to protect the Kubernetes environment from unauthorized access and potential security breaches. The detection is made by using the Splunk query aws_cloudwatchlogs_eks with specific filters to identify these requests. Identifies events where the user.username is set to "system:anonymous", the verb is set to "list", and the objectRef.resource is set to "pods". Additionally, the search checks if the requestURI is equal to "/api/v1/pods". Analyzing these events helps you to identify any unauthorized access attempts to the Kubernetes' Pods API. Unauthenticated requests can indicate potential security breaches or unauthorized access to sensitive resources within the Kubernetes environment. The detection is important because unauthorized access to Kubernetes' Pods API can lead to the compromise of sensitive data, unauthorized execution of commands, or even the potential for lateral movement within the Kubernetes cluster. False positives might occur since there might be legitimate use cases for unauthenticated requests in certain scenarios. Therefore, you must review and validate any detected events before taking any action. Next steps include investigating the incident to mitigate any ongoing threats, and strengthening the security measures to prevent future unauthorized access attempts.

  • Type: Hunting

  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud

  • Last Updated: 2020-04-15
  • Author: Rod Soto, Splunk
  • ID: dbfca1dd-b8e5-4ba4-be0e-e565e5d62002

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1526 Cloud Service Discovery Discovery
Kill Chain Phase
  • Exploitation
NIST
  • DE.AE
CIS20
  • CIS 10
CVE 


1
2
3
4
5
6



`aws_cloudwatchlogs_eks` "user.username"="system:anonymous" verb=list objectRef.resource=pods requestURI="/api/v1/pods" 
| rename source as cluster_name sourceIPs{} as src_ip 
| stats count min(_time) as firstTime max(_time) as lastTime values(responseStatus.reason) values(responseStatus.code) values(userAgent) values(verb) values(requestURI) by src_ip cluster_name user.username user.groups{} 
| `security_content_ctime(lastTime)` 
| `security_content_ctime(firstTime)` 
| `amazon_eks_kubernetes_pod_scan_detection_filter`

Macros

The SPL above uses the following Macros:

:information_source: amazon_eks_kubernetes_pod_scan_detection_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Required fields

List of fields required to use this analytic.

  • _time
  • user.username
  • verb
  • objectRef.resource
  • requestURI
  • source
  • sourceIPs{}
  • responseStatus.reason
  • responseStatus.code
  • userAgent
  • src_ip
  • user.groups{}

How To Implement

You must install the AWS App for Splunk (version 5.1.0 or later) and Splunk Add-on forAWS (version 4.4.0 or later), then configure your AWS CloudWatch EKS Logs.Please also customize the kubernetes_pods_aws_scan_fingerprint_detection macro to filter out the false positives.

Known False Positives

Not all unauthenticated requests are malicious, but frequency, UA and source IPs and direct request to API provide context.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
25.0 50 50 tbd

:information_source: The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

Reference

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

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