Windows Node.exe Executing JS Script In Immediate Folder
Description
The following analytic identifies node.exe directly executing a single .js script located in the same directory it was launched from, where that directory is an unusual location such as a user profile, PerfLogs, ProgramData, or Temp folder.
Legitimate Node.js application, module, and package manager directories are excluded.
This pattern is commonly associated with malware loaders and second-stage payloads that leverage the Node.js runtime to execute JavaScript outside of a typical development or application context.
Query · spl
| tstats `security_content_summariesonly`
count min(_time) as firstTime
max(_time) as lastTime
FROM datamodel=Endpoint.Processes WHERE
(
Processes.process_name="node.exe"
OR
Processes.original_file_name="node.exe"
)
Processes.process="*js"
Processes.process_path IN (
"*:\\PerfLogs\\*",
"*:\\ProgramData\\*",
"*:\\Temp\\*",
"*:\\Users\\*"
)
(
NOT Processes.process_path IN (
"*\\AppData\\Roaming\\*",
"*\\node\\*",
"*\\nodejs\\*",
"*\\nvm\\*"
)
AND
(
NOT Processes.process_path = "*\\AppData\\Local\\*"
OR
Processes.process_path = "*\\AppData\\Local\\Temp\\*"
)
)
by Processes.action Processes.dest Processes.original_file_name
Processes.parent_process Processes.parent_process_exec
Processes.parent_process_guid Processes.parent_process_id
Processes.parent_process_name Processes.parent_process_path
Processes.process Processes.process_exec Processes.process_guid
Processes.process_hash Processes.process_id
Processes.process_integrity_level Processes.process_name
Processes.process_path Processes.user Processes.user_id
Processes.process_current_directory Processes.vendor_product
| `drop_dm_object_name(Processes)`
| eval process_args=split(process, " ")
| eval script_name=mvindex(process_args, 1)
| eval process_args_count=mvcount(process_args)
| regex script_name="(?i)^[^\\\/]+\.js$"
| where like(process_path, process_current_directory.process_name) AND process_args_count=2
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `windows_node_exe_executing_js_script_in_immediate_folder_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
- Legitimate custom Node.js tooling or utility scripts that are intentionally placed and executed from a user profile, PerfLogs, ProgramData, or Temp directory may trigger this analytic.
Analyst notes
Known false positives: Legitimate custom Node.js tooling or utility scripts that are intentionally placed and executed from a user profile, PerfLogs, ProgramData, or Temp directory may trigger this analytic.