| ID | Technique | Tactic |
|---|---|---|
| T1190 | Exploit Public-Facing Application | Initial Access |
| T1059.003 | Windows Command Shell | Execution |
| T1059.001 | PowerShell | Execution |
Detection: 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.
Search
1
2| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime
3 from datamodel=Endpoint.Processes
4 where
5 Processes.parent_process_name = "node.exe"
6 Processes.parent_process IN (
7 "*--experimental-https*",
8 "*--experimental-next-config-strip-types*",
9 "*\\node_modules\\next*",
10 "*next dev*",
11 "*next start*",
12 "*next\" start*",
13 "*node_modules\\.bin\\\\..\\next*",
14 "*react-scripts start*",
15 "*start-server.js*",
16 )
17 AND
18 (
19 Processes.process_name IN (
20 "bash.exe",
21 "bitsadmin.exe",
22 "calc.exe",
23 "certutil.exe",
24 "cscript.exe",
25 "curl.exe",
26 "ftp.exe",
27 "ipconfig.exe",
28 "mshta.exe",
29 "netstat.exe",
30 "OpenConsole.exe",
31 "powershell.exe",
32 "pwsh.exe",
33 "regsvr32.exe",
34 "rundll32.exe",
35 "sh.exe",
36 "tftp.exe",
37 "wget.exe",
38 "wmic.exe",
39 "wscript.exe",
40 "wsl.exe",
41 "wt.exe"
42 )
43 OR
44 (
45 Processes.process_name = "cmd.exe"
46 AND NOT Processes.process = "*/d /s /c *"
47 )
48 OR
49 (
50 Processes.process_name = "cmd.exe"
51 Processes.process = "*/d /s /c *"
52 AND NOT (
53 Processes.process = "*git config --local --get remote.origin.url*"
54 OR
55 (
56 Processes.process = "*netstat -ano
57| findstr /C:*"
58 Processes.process = "*
59| findstr LISTENING*"
60 )
61 OR
62 (
63 Processes.parent_process = "*--experimental-https*"
64 Processes.process = "*\\mkcert\\*"
65 Processes.process IN ("* -CAROOT*", "* -install *")
66 )
67 )
68 )
69 )
70by Processes.action Processes.dest Processes.original_file_name Processes.parent_process
71 Processes.parent_process_exec Processes.parent_process_guid Processes.parent_process_id
72 Processes.parent_process_name Processes.parent_process_path Processes.process
73 Processes.process_exec Processes.process_guid Processes.process_hash Processes.process_id
74 Processes.process_integrity_level Processes.process_name Processes.process_path
75 Processes.user Processes.user_id Processes.vendor_product
76
77
78| `drop_dm_object_name(Processes)`
79
80| `security_content_ctime(firstTime)`
81
82| `security_content_ctime(lastTime)`
83
84| `windows_suspicious_react_or_next_js_child_process_filter`
Data Source
| Name | Platform | Sourcetype | Source |
|---|---|---|---|
| CrowdStrike ProcessRollup2 | Other | 'crowdstrike:events:sensor' |
'crowdstrike' |
| Sysmon EventID 1 | 'XmlWinEventLog' |
'XmlWinEventLog:Microsoft-Windows-Sysmon/Operational' |
|
| Windows Event Log Security 4688 | 'XmlWinEventLog' |
'XmlWinEventLog:Security' |
Macros Used
| Name | Value |
|---|---|
| security_content_ctime | convert timeformat="%Y-%m-%dT%H:%M:%S" ctime($field$) |
| windows_suspicious_react_or_next_js_child_process_filter | search * |
windows_suspicious_react_or_next_js_child_process_filter is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.
Annotations
Default Configuration
This detection is configured by default in Splunk Enterprise Security to run with the following settings:
| Setting | Value |
|---|---|
| Disabled | true |
| Cron Schedule | 0 * * * * |
| Earliest Time | -70m@m |
| Latest Time | -10m@m |
| Schedule Window | auto |
| Creates Notable | Yes |
| Rule Title | %name% |
| Rule Description | %description% |
| Notable Event Fields | user, dest |
| Creates Risk Event | True |
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
Rare false positives might show up from child processes such as cmd or powershell. Apply additional filters as needed.
Associated Analytic Story
Risk Based Analytics (RBA)
Risk Message:
A Node-based server process ($parent_process_name$) spawned the child process $process_name$ with command-line $process$ on host $dest$ by user $user$, which may indicate remote code execution via React Server Components (CVE-2025-55182 / React2Shell) or abuse of a similar Node.js RCE vector.
| Risk Object | Risk Object Type | Risk Score | Threat Objects |
|---|---|---|---|
| dest | system | 70 | parent_process_name, process, process_name |
| user | user | 70 | parent_process_name, process, process_name |
References
-
https://react.dev/blog/2025/12/03/critical-security-vulnerability-in-react-server-components
-
https://gist.github.com/maple3142/48bc9393f45e068cf8c90ab865c0f5f3
-
https://www.wiz.io/blog/critical-vulnerability-in-react-cve-2025-55182
Detection Testing
| Test Type | Status | Dataset | Source | Sourcetype |
|---|---|---|---|---|
| Validation | ✅ Passing | N/A | N/A | N/A |
| Unit | ✅ Passing | Dataset | XmlWinEventLog:Microsoft-Windows-Sysmon/Operational |
XmlWinEventLog |
| Integration | ✅ Passing | Dataset | XmlWinEventLog:Microsoft-Windows-Sysmon/Operational |
XmlWinEventLog |
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