Technical preview

To unlock the full functionality of the Defend for Containers (D4C) integration, you'll need to understand its policy syntax. This will enable you to construct policies that precisely allow expected container behaviors and prevent unexpected behaviors — thereby hardening your container workloads' security posture.

D4C integration policies consist of selectors and responses. Each policy must contain at least one selector and one response. Currently, the system supports two types of selectors and responses: file and process. Selectors define which system operations to match and can include multiple conditions (grouped using a logical AND) to precisely select events. Responses define which actions to take when a system operation matches the conditions specified in an associated selector.

The default policy described on this page provides an example that's useful for understanding D4C policies in general. Following the description, you'll find a comprehensive glossary of selector conditions, response fields, and actions.

Default policies:

The default D4C integration policy includes two selector-response pairs. It is designed to implement core container workload protection capabilities:

• Threat Detection: The first selector-response pair is designed to stream process telemetry data to your Elasticsearch cluster so Elastic Security can evaluate it to detect threats. Both the selector and response are named allProcesses. The selector selects all fork and exec events. The associated response specifies that selected events should be logged.
• Drift Detection & Prevention: The second selector-response pair is designed to create alerts when container drift is detected. Both the selector and response are named executableChanges. The selector selects all createExecutable and modifyExecutable events. The associated response specifies that the selected events should create alerts, which will be sent to your Elasticsearch cluster. You can modify the response to block drift operations by setting it to block.

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Selectors

A selector requires a name and at least one operation. It will select all events of the specified operation types, unless you also include conditions to narrow down the selection. Some conditions are available for both file and process selectors, while others only available for one type of selector.

Common conditions

These conditions are available for both file and process selectors.

Name	Description
containerImageFullName	A list of full container image names to match on. For example: docker.io/nginx.
containerImageName	A list of container image names to match on. For example: nginx.
containerImageTag	A list of container image tags to match on. For example: latest.
kubernetesClusterId	A list of Kubernetes cluster IDs to match on. For consistency with KSPM, the kube-system namespace's UID is used as a cluster ID.
kubernetesClusterName	A list of Kubernetes cluster names to match on.
kubernetesNamespace	A list of Kubernetes namespaces to match on.
kubernetesPodName	A list of Kubernetes pod names to match on. Trailing wildcards supported.
kubernetesPodLabel	A list of resource labels. Trailing wildcards supported (value only), for example: key1:val*.

File-selector conditions

These conditions are available only for file selectors.

Name	Description
operation	The list of system operations to match on. Options include createExecutable, modifyExecutable, createFile, modifyFile, deleteFile.
ignoreVolumeMounts	If set, ignores file operations on all volume mounts.
ignoreVolumeFiles	If set, ignores operations on file mounts only. For example: mounted files, configMaps, and secrets.
targetFilePath	A list of file paths to include. Paths are absolute and wildcards are supported. The * wildcard matches any sequence of characters within a single directory, while the ** wildcard matches any sequence of characters across multiple directories and subdirectories.

Process-selector conditions

These conditions are available only for process selectors.

Name	Description
operation	The list of system operations to match on. Options include fork and exec.
processExecutable	A list of executables (full path included) to match on. For example: /usr/bin/cat. Wildcard support is same as targetFilePath above.
processName	A list of process names (executable basename) to match on. For example: bash, vi, cat.
sessionLeaderInteractive	If set to true, will only match on interactive sessions (defined as sessions with a controlling TTY).

Response fields

A policy can include one or more responses. Each response is comprised of the following fields:

Field	Description
match	An array of one or more selectors of the same type (file or process).
exclude	Optional. An array of one or more selectors to use as exclusions to everything in match.
actions	An array of actions to perform when at least one match selector matches and none of the exclude selectors match. Options include log, alert, and block.

Response actions

D4C responses can include the following actions:

Action	Description
log	Sends events to the logs-cloud_defend.file-* data stream for file responses, and the logs-cloud_defend.process-* data stream for process responses.
alert	Writes events (file or process) to the logs-cloud_defend.alerts-* data stream.
block	Prevents the system operation from proceeding. This blocking action happens prior to the execution of the event. It is required that the alert action be set if block is enabled. Note: Currently, block is only supported on file operations.