Windows Suspicious React or Next.js Child Process
Description
This analytic detects Windows processes such as cmd.exe, PowerShell, and common Windows LOLBINs being spawned by React or Next.js application servers. In the context of CVE-2025-55182 / React2Shell / CVE-2025-66478 for Next.js, successful exploitation can lead to arbitrary JavaScript execution on the server, which in turn is used to invoke Node's child_process APIs (for example child_process.execSync) to run OS-level commands. This detection focuses on suspicious child processes where a Next/React server process spawns an uncommon process. Such activity might be a strong indicator of exploitation of the aforementioned vulnerability.
Query · spl
| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime
from datamodel=Endpoint.Processes
where
Processes.parent_process_name = "node.exe"
Processes.parent_process IN (
"*--experimental-https*",
"*--experimental-next-config-strip-types*",
"*\\node_modules\\next*",
"*next dev*",
"*next start*",
"*next\" start*",
"*node_modules\\.bin\\\\..\\next*",
"*react-scripts start*",
"*start-server.js*",
)
AND
(
Processes.process_name IN (
"bash.exe",
"bitsadmin.exe",
"calc.exe",
"CalculatorApp.exe",
"certutil.exe",
"cscript.exe",
"curl.exe",
"ftp.exe",
"ipconfig.exe",
"mshta.exe",
"netstat.exe",
"OpenConsole.exe",
"powershell.exe",
"pwsh.exe",
"regsvr32.exe",
"rundll32.exe",
"sh.exe",
"tftp.exe",
"wget.exe",
"win32calc.exe",
"wmic.exe",
"wscript.exe",
"wsl.exe",
"wt.exe"
)
OR
(
Processes.process_name = "cmd.exe"
AND NOT Processes.process = "*/d /s /c *"
)
OR
(
Processes.process_name = "cmd.exe"
Processes.process = "*/d /s /c *"
AND NOT (
Processes.process = "*git config --local --get remote.origin.url*"
OR
(
Processes.process = "*netstat -ano | findstr /C:*"
Processes.process = "* | findstr LISTENING*"
)
OR
(
Processes.parent_process = "*--experimental-https*"
Processes.process = "*\\mkcert\\*"
Processes.process IN ("* -CAROOT*", "* -install *")
)
)
)
)
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.vendor_product
| `drop_dm_object_name(Processes)`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `windows_suspicious_react_or_next_js_child_process_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
- Rare false positives might show up from child processes such as cmd or powershell. Apply additional filters as needed.
Analyst notes
Known false positives: Rare false positives might show up from child processes such as cmd or powershell. Apply additional filters as needed.