Malicious code in tsihealth-client (npm)

The npm package tsihealth-client contained a self-decoding IIFE (Immediately Invoked Function Expression) in its index.js that XOR-decodes a URI-encoded payload at module load time. The decoder includes anti-tampering logic that aborts with 'the code has been tampered!' if the source is modified, and includes a banner discouraging reverse engineering.\n\nThe package's metadata and TypeScript definitions reveal the malicious intent: package.json advertises it as a 'client (provider) for the tsi-vpsremote control server' that 'stays alive to run commands pushed from the server', with keywords including 'shell', 'ssh', 'remote-control', and 'agent'. The exported TypeScript interface includes a ProviderHandle exposing a ChildProcess named shell.\n\nWhen the exported provider function is called at runtime with a URL parameter, it establishes a persistent connection to a remote server that can drive a local ChildProcess on the host. This creates a full network-to-shell control channel, granting whoever controls the paired server URL arbitrary command execution on any system running the package.\n\nThe decoded payload itself is opaque and cannot be audited without executing the malicious code. This incident was identified by the OpenSSF's malicious-packages project.