Linux Suspicious Docker Build Command Execution
Description
The following analytic detects docker build being executed on Dockerfiles within the /tmp directory. This is not a typical location for this activity and can indicate an actor adding a container for malicious future actions.
Query · spl
| tstats `security_content_summariesonly`
count min(_time) as firstTime max(_time) as lastTime
from datamodel=Endpoint.Processes where
Processes.process="*docker*"
Processes.process="*build*"
(
(
Processes.process="*-f *"
Processes.process="* /tmp*"
)
OR
Processes.process_current_directory="/tmp*"
)
by Processes.process Processes.vendor_product Processes.user_id Processes.process_hash
Processes.parent_process_name Processes.parent_process_exec Processes.action Processes.dest
Processes.process_current_directory Processes.process_path Processes.process_integrity_level
Processes.original_file_name Processes.parent_process Processes.parent_process_path
Processes.parent_process_guid Processes.parent_process_id Processes.process_guid
Processes.process_id Processes.user Processes.process_name
| `drop_dm_object_name(Processes)`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `linux_suspicious_docker_build_command_execution_filter`
Implementation guide
The detection is based on data that originates from Endpoint Detection and Response (EDR) agents. These agents are designed to provide security-related telemetry from the endpoints where the agent is installed. To implement this search, you must ingest logs that contain the process GUID, process name, and parent process. Additionally, you must ingest complete command-line executions. These logs must be processed using the appropriate Splunk Technology Add-ons that are specific to the EDR product. The logs must also be mapped to the Processes node of the Endpoint data model. Use the Splunk Common Information Model (CIM) to normalize the field names and speed up the data modeling process.
Known false positives
- Developers or administrators may occasionally use the /tmp directory for testing Docker builds in non-production environments. Filter based on known users or systems where this activity has been approved.
Analyst notes
Known false positives: Developers or administrators may occasionally use the /tmp directory for testing Docker builds in non-production environments. Filter based on known users or systems where this activity has been approved.