AWS EKS Suspicious Assignment of Controller Service Account

Last updated 2 days ago on 2026-10-21

Created 3 months ago on 2026-08-03

About

This rule detects a request to attach a controller service account to an existing or new pod running in the kube-system namespace. By default, controllers running as part of the API Server utilize admin-equivalent service accounts hosted in the kube-system namespace. Controller service accounts aren't normally assigned to running pods and could indicate adversary behavior within the cluster. An attacker that can create or modify pods or pod controllers in the kube-system namespace, can assign one of these admin-equivalent service accounts to a pod and abuse their powerful token to escalate privileges and gain complete cluster control.

Tags

Domain: CloudDomain: ContainersPlatform: AWSPlatform: KubernetesData Source: AWSData Source: Amazon Web ServicesData Source: Kubernetes API Server Audit LogsService: AWS EKSUse Case: Threat DetectionTactic: Privilege EscalationRule Type: Custom Query (KQL)Profile: BetaLanguage: kuery

Severity

medium

Risk Score

MITRE ATT&CK™

Privilege Escalation (TA0004)(external, opens in a new tab or window)

↳ Valid Accounts (T1078)(external, opens in a new tab or window)

False Positive Examples

Controller service accounts aren't normally assigned to running pods, this is abnormal behavior with very few legitimate use-cases and should result in very few false positives.

License

Elastic License v2(external, opens in a new tab or window)

Definition

Rule Type: Query (Kibana Query Language)
Integration Pack: Prebuilt Security Detection Rules
Index Patterns: logs-aws.eks_audit-*
Related Integrations: aws(external, opens in a new tab or window)
Query

✄𐘗text code block:
✄𐘗data_stream.dataset : "aws.eks_audit" and aws.eks.audit.annotations.authorization_k8s_io/decision:"allow" and
aws.eks.audit.verb : "create" and aws.eks.audit.objectRef.resource : "pods" and
aws.eks.audit.objectRef.namespace : "kube-system" and aws.eks.audit.requestObject.spec.serviceAccountName:*controller and
not aws.eks.audit.requestObject.spec.containers.image:(
  mirror.gcr.io/aquasec/trivy* or *amazonaws.com/eks/snapshot-controller* or rancher/mirrored-sig-storage-snapshot-controller* or
  public.ecr.aws/eks/aws-load-balancer-controller* or docker.io/bitnami/sealed-secrets-controller* or
  registry.k8s.io/autoscaling/vpa-admission-controller* or registry.k8s.io/sig-storage/csi-attacher* or registry.k8s.io/sig-storage/csi-provisioner*
)

Install detection rules in Elastic Security

Detect AWS EKS Suspicious Assignment of Controller Service Account in the Elastic Security detection engine by installing this rule into your Elastic Stack.

To setup this rule, check out the installation guide for Prebuilt Security Detection Rules(external, opens in a new tab or window).