Kubelet Certificate File Access Detected via Defend for Containers

Last updated 2 days ago on 2026-02-09
Created 9 days ago on 2026-02-02

About

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.
Tags
Data Source: Elastic Defend for ContainersDomain: ContainerOS: LinuxUse Case: Threat DetectionTactic: DiscoveryLanguage: eql
Severity
low
Risk Score
21
MITRE ATT&CK™

Discovery (TA0007)(external, opens in a new tab or window)

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

Definition

Rule Type
Event Correlation Rule
Integration Pack
Prebuilt Security Detection Rules
Index Patterns
logs-cloud_defend.file*logs-cloud_defend.process*
Related Integrations

cloud_defend(external, opens in a new tab or window)

Query
text code block:
any where host.os.type == "linux" and process.interactive == true and container.id like "*" and ( (event.category == "file" and event.type == "change" and event.action == "open" and file.path like "/var/lib/kubelet/pki/*") or (event.category == "process" and event.type == "start" and event.action == "exec" and ( process.name in ("cat", "head", "tail", "more", "less", "sed", "awk") or process.args in ( "cat", "/bin/cat", "/usr/bin/cat", "/usr/local/bin/cat", "head", "/bin/head", "/usr/bin/head", "/usr/local/bin/head", "tail", "/bin/tail", "/usr/bin/tail", "/usr/local/bin/tail", "more", "/bin/more", "/usr/bin/more", "/usr/local/bin/more", "less", "/bin/less", "/usr/bin/less", "/usr/local/bin/less", "sed", "/bin/sed", "/usr/bin/sed", "/usr/local/bin/sed", "awk", "/bin/awk", "/usr/bin/awk", "/usr/local/bin/awk" ) ) and process.args like "*/var/lib/kubelet/pki/*") )

Install detection rules in Elastic Security

Detect Kubelet Certificate File Access Detected via Defend for Containers 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).