Supply chain · rubygems · High

Critical RubyGems Package 'web3-sign-helper' Identified as Malicious Dropper

Threat Engine Auto-Feed · data current as of 2026-10-05

The RubyGems package `web3-sign-helper` version 1.0.0 contains malicious code designed to execute a remote code execution dropper during installation. This package employs sophisticated anti-analysis techniques to evade detection in CI/sandbox environments and targets developer workstations for credential and secret theft.

  • Package: rubygems / web3-sign-helper
  • Affected versions: = 1.0.0
  • Severity: critical
  • Reach: unknown
  • Exposure: 65/100 (High)

What happened — Credential / secret theft

The `web3-sign-helper` gem, version 1.0.0, was found to contain malicious code. During installation, its `extconf.rb` script executes a base64-decoded Ruby payload. This payload downloads and executes a tarball from a reconstructed URL, running a bash script in a detached process. The attack is designed to evade detection in CI/sandbox environments and specifically targets developer workstations.

How the attack works

This is a supply-chain attack leveraging a malicious software package. The package disguises a remote code execution dropper as a native build step. It uses anti-analysis checks, including inspecting CI environment variables, hostnames, user patterns, working directories, system uptime, and the presence of developer-identity artifacts, to ensure execution only on suitable targets. Once these checks pass, it downloads and executes an external script, leading to potential credential and secret theft.

Who's exposed

Profiles most at risk

  • Organizations and teams using the RubyGems ecosystem
  • Developers who have installed or built projects depending on `web3-sign-helper` version 1.0.0
  • CI/CD pipelines that pull unpinned or latest versions of dependencies

Conditions that increase exposure

  • Direct or transitive dependency on `web3-sign-helper` version 1.0.0
  • Lack of dependency pinning or lockfiles in build processes
  • Use of internal mirrors that may not filter malicious packages
  • Developer workstations with common developer-identity artifacts (e.g., ~/.ssh, ~/.gitconfig, ~/.gem/credentials, ~/.bundle)

Blast-radius scenarios

  • If installed, an attacker can achieve remote code execution on the affected system, potentially leading to credential and secret theft.
  • Compromised developer workstations could expose sensitive source code, API keys, or access tokens.
  • The detached execution of the downloaded script makes detection and containment challenging post-installation.

What to do (defensive)

Detect

  • Scan dependency trees for `web3-sign-helper` version 1.0.0.
  • Monitor network traffic for outbound connections from build environments or developer machines to unusual URLs, especially after package installations.
  • Review system logs for unexpected process execution, particularly `curl` or `bash` commands originating from package installation directories or `/tmp`.

Contain

  • Immediately quarantine any systems identified with `web3-sign-helper` version 1.0.0 installed.
  • Block network access to the reconstructed download URL (if identified) from all build and developer environments.
  • Revoke and rotate any credentials or secrets that may have been present on compromised developer workstations.

Remediate

  • Remove `web3-sign-helper` version 1.0.0 from all dependency lists and lockfiles.
  • Rebuild affected applications and environments without the malicious package.
  • Implement strict dependency pinning and review processes for all third-party packages.
  • Educate developers on the risks of supply-chain attacks and the importance of verifying package authenticity.

Frontier verdict — High

Prioritize immediate removal of `web3-sign-helper` version 1.0.0 and a thorough audit of developer workstations due to critical remote code execution risk.

Sources

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