Kubelet Certificate File Access Detected via Defend for Containers
This rule detects the access of the Kubelet certificate file inside a container. The Kubelet certificate file is used to authenticate the container to the Kubernetes API server, and may be used by an adversary to…
Description
This rule detects the access of the Kubelet certificate file inside a container. The Kubelet certificate file is used to authenticate the container to the Kubernetes API server, and may be used by an adversary to gain access to the Kubernetes API server or other resources within the cluster. These files are a common target for adversaries to gain access to the cluster. There is a current limitation in the defend for containers file sensor that prevents file open events from being logged for file open events without write intent.
Detection logic
Its licence does not clear it for publishing here
Sunturai publishes a detection's own text where the licence it arrived under has been reviewed and permits it, and Elastic License 2.0 has not. The query as its source wrote it, its canonical form and the hash that pins this revision are in the workspace record.
Detection requirements
- Platform
- ContainersIaaSIdentity ProviderLinuxmacOSNetwork DevicesOffice SuiteSaaSWindows
The rule states no platform. This is derived from the 2 ATT&CK techniques it maps to.
- Log source category
- event_index
MITRE ATT&CK mappings
0 exclusive techniques.This is coverage no other published rule has; it is not this rule's total technique count.
References
| Reference | Cited by |
|---|---|
| heilancoos.github.io/research/2025/12/16/kubernetes.html#kubelet-api | 21 |
| www.aquasec.com/blog/kubernetes-exposed-exploiting-the-kubelet-api/ | 5 |
| www.cyberark.com/resources/threat-research-blog/using-kubelet-client-to-attack-the-kubernetes-cluster | 8 |
From the source
- At source
- Open at source
- Upstream identifier
- 42de0740-8ed8-4b8b-995c-635b56a8bbf4
- Tagged by the source as
- Data Source: Elastic Defend for ContainersDomain: ContainersNoise: UnknownOS: LinuxPerformance: FastPlatform: KubernetesPlatform: LinuxResources: Investigation GuideRule Type: Event Correlation (EQL)Tactic: DiscoveryUse Case: Threat Detection
Licence
- Published under
- Elastic License 2.0Read the licence
- Attribution
- Required
Authorship
- Written by
- Published
- Sep 20, 2026
- Version
- 3