Potential Java WebShell Upload in SAP NetViewer Server

Detects potential Java webshell uploads via HTTP requests with Content-Type 'application/octet-stream' and Java file extensions. This behavior might indicate exploitation of vulnerabilities like CVE-2025-31324, which allows remote code execution through webshells in SAP NetViewer.

title: Potential Java WebShell Upload in SAP NetViewer Server
id: 639b893f-f93a-4e53-a7c8-f08cf73fe7f7
status: experimental
description: |
    Detects potential Java webshell uploads via HTTP requests with Content-Type 'application/octet-stream' and Java file extensions.
    This behavior might indicate exploitation of vulnerabilities like CVE-2025-31324, which allows remote code execution through webshells in SAP NetViewer.
references:
    - https://blog.eclecticiq.com/china-nexus-nation-state-actors-exploit-sap-netweaver-cve-2025-31324-to-target-critical-infrastructures
author: Swachchhanda Shrawan Poudel (Nextron Systems)
date: 2025-05-14
tags:
    - attack.persistence
    - attack.t1505.003
    - detection.emerging-threats
    - cve.2025-31324
logsource:
    category: webserver
detection:
    selection:
        cs-content-type: 'application/octet-stream'
        cs-method: 'POST'
        cs-uri-stem|contains|all:
            - '/irj/'
            - '.jsp'
        cs-uri-stem|endswith:
            - '.class'
            - '.java'
            - '.jsp'
    condition: selection
falsepositives:
    - Legitimate uploads of Java files in development environments
level: high

• T1505.003Web Shell

• https://blog.eclecticiq.com/china-nexus-nation-state-actors-exploit-sap-netweaver-cve-2025-31324-to-target-critical-infrastructures↗