Detection: 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.

Search

 1
 2| tstats `security_content_summariesonly`
 3  count min(_time) as firstTime max(_time) as lastTime
 4
 5from datamodel=Endpoint.Processes where
 6
 7Processes.process="*docker*"
 8Processes.process="*build*"
 9(
10    (
11        Processes.process="*-f *"
12        Processes.process="* /tmp*"
13    )
14    OR
15    Processes.process_current_directory="/tmp*"
16)
17
18by Processes.process Processes.vendor_product Processes.user_id Processes.process_hash
19   Processes.parent_process_name Processes.parent_process_exec Processes.action Processes.dest
20   Processes.process_current_directory Processes.process_path Processes.process_integrity_level
21   Processes.original_file_name Processes.parent_process Processes.parent_process_path
22   Processes.parent_process_guid Processes.parent_process_id Processes.process_guid
23   Processes.process_id Processes.user Processes.process_name
24
25
26| `drop_dm_object_name(Processes)`
27
28| `security_content_ctime(firstTime)`
29
30| `security_content_ctime(lastTime)`
31
32| `linux_suspicious_docker_build_command_execution_filter`

Data Source

Name	Platform	Sourcetype	Source
Sysmon for Linux EventID 1	Linux	'sysmon:linux'	'Syslog:Linux-Sysmon/Operational'

Macros Used

Annotations

Default Configuration

This detection is configured by default in Splunk Enterprise Security to run with the following settings:

Implementation

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.

Associated Analytic Story

• Linux Post-Exploitation

Intermediate Findings

Threat Objects

References

• https://github.com/Aegrah/PANIX

Detection Testing

Replay any dataset to Splunk Enterprise by using our replay.py tool or the UI. Alternatively you can replay a dataset into a Splunk Attack Range

Source: GitHub |

Version: 1