multer-orm is a malicious npm package designed as a typosquat of the popular multer middleware. Its README is copied from multer to appear legitimate, but the package contains a malicious script in lib/feature.js that executes upon requiring the module. On Windows, it fetches a JSON payload from a remote server to obtain a downloader URL, downloads a binary into the Chrome User Data directory as chrome.exe, marks it executable, and runs it. If the Node.js process lacks admin rights, it attempts to elevate privileges using PowerShell. It then disables Windows Defender scanning on approximately twenty directories, including browser user data paths, by adding exclusions via PowerShell commands executed through cscript.exe. The malicious code and configuration are obfuscated. The package also declares a self-referential dependency on itself. This results in arbitrary remote code execution with privilege escalation and antivirus tampering on Windows systems.

Installing or requiring multer-orm on a Windows machine leads to arbitrary remote code execution with an attempt to escalate privileges to administrator. The malware disables Windows Defender scanning on multiple directories, including browser user data folders, allowing persistence and evasion of detection. This compromises system integrity and security, potentially allowing further malicious actions by the attacker.

No official patch or remediation is currently available for multer-orm as it is a malicious typosquat package. The best mitigation is to avoid installing or requiring this package. Use only the legitimate multer package from trusted sources. Monitor npm dependencies for typosquat or suspicious packages. Remove any instances of multer-orm from your environment immediately. Employ endpoint protection solutions that can detect and block such malicious behaviors. Patch status is not yet confirmed — check vendor advisories or npm security advisories for updates.