Supply chain · npm · High

Critical Malicious npm Package: 'tsihealth-client' Establishes Remote Control

Threat Engine Auto-Feed · data current as of 2026-08-06

A critical malicious package, 'tsihealth-client' version 1.0.1, was identified in the npm ecosystem. This package establishes a persistent remote control channel, allowing an attacker to execute arbitrary commands on the host where it is installed. Organizations using this package are at high risk of full system compromise.

  • Package: npm / tsihealth-client
  • Affected versions: = 1.0.1
  • Severity: critical
  • Reach: unknown
  • Exposure: 65/100 (High)

What happened — Malicious package

The npm package 'tsihealth-client' version 1.0.1 contains malicious code designed to establish a remote control channel. Upon installation and execution, the package connects to a remote server and executes commands pushed from that server on the local host. The package's metadata explicitly describes its function as a 'client (provider) for the tsi-vpsremote control server' that 'stays alive to run commands pushed from the server', indicating its intent for remote command execution.

How the attack works

This attack leverages a malicious software package to create an unauthorized communication channel. The package, when run, connects to an external server. This connection allows the server to send commands back to the host running the package, which are then executed locally. This effectively grants an attacker remote command execution capabilities on the compromised system.

Who's exposed

Profiles most at risk

  • Development teams using the npm ecosystem
  • Organizations with CI/CD pipelines that pull unpinned or latest versions of npm packages
  • Any system or application that has 'tsihealth-client' version 1.0.1 as a dependency

Conditions that increase exposure

  • Unpinned dependencies in package.json allowing automatic updates to malicious versions
  • Lack of package-lock.json or yarn.lock files to ensure consistent dependency resolution
  • Use of internal package mirrors that do not vet packages against known advisories
  • Direct or transitive dependency on 'tsihealth-client' version 1.0.1

Blast-radius scenarios

  • An attacker gains full command execution on the host where the package is installed, leading to data exfiltration, further network compromise, or system disruption.
  • Compromised build environments or developer workstations if the package is installed during development or CI processes.
  • Production systems running applications that include the malicious package, leading to critical service disruption or data breaches.

What to do (defensive)

Detect

  • Scan dependency trees for 'tsihealth-client' version 1.0.1.
  • Monitor network traffic for outbound connections from development or production systems to unknown or suspicious remote control servers.
  • Review package-lock.json or yarn.lock files for the presence of the affected package.

Contain

  • Isolate any systems identified as having installed 'tsihealth-client' version 1.0.1.
  • Block network connections to known or suspected command-and-control (C2) infrastructure associated with this package.
  • Prevent further installation of 'tsihealth-client' version 1.0.1 across all environments.

Remediate

  • Remove 'tsihealth-client' version 1.0.1 from all dependency lists and package-lock files.
  • Rebuild affected applications and redeploy to clean environments after ensuring the malicious package is no longer present.
  • Perform a thorough forensic analysis on any systems where the package was installed to identify the extent of compromise and remove any persistent attacker access.

Frontier verdict — High

Prioritize immediate detection and removal of 'tsihealth-client' version 1.0.1 due to its critical severity and remote command execution capabilities.

Sources

For detection-engineering and awareness only · point-in-time · not security advice · sourced from the GitHub Advisory Database.