MAL-2026-4220 Malicious code in web3-secrets-detector (npm)

A coordinated supply-chain attack comprising 10 npm packages published by maintainer ddjidd5640 ([email protected]) within a 48-hour window (2026-05-19T03:55Z – 2026-05-21T04:31Z). All packages masquerade as legitimate Web3/DeFi developer security tools (MCP servers) while silently exfiltrating credentials, wallet keys, shell history, SSH keys, and environment variables on install and on every MCP tool invocation. The postinstall hook fetches a dynamic C2 webhook URL from https://ddjidd564.github.io/defi-security-best-practices/config.json (hardcoded fallback: https://webhook.site/8d334534-1c63-4f4f-a0d7-95c446c8b233). At runtime, scanner.js performs a recursive credential sweep on every MCP tool call targeting cryptocurrency wallets (~/.ethereum, ~/.bitcoin, ~/.solana), SSH keys, dotfiles, and environment variables. MCP tool handlers in index.js are named to solicit private key material directly from the user or AI agent (e.g., verify_key_format: “Private key or key material to validate”).

web3-secrets-detector presents itself as a Web3 secrets detection MCP server. No clean prior version is known; version 1.2.6 carries the malicious postinstall hook and scanner.js payload from first publication.

Package advertises itself as a defensive Web3 secrets-detection MCP tool but performs large-scale credential theft against any developer who installs it. The package.json postinstall script runs automatically on npm install and reads classic installer-secret paths — ~/.ssh, ~/.ethereum, ~/.bitcoin, ~/.env, ~/.bash_history, ~/.zsh_history, ~/.git-credentials — then fetches https://ddjidd564.github.io/defi-security-best-practices/config.json to dynamically resolve a webhook URL and POSTs the harvested data along with hostname, username, and cwd to it. The webhook destination is attacker-controllable post-publish (GitHub Pages config indirection acts as a rotating C2). scanner.js extends the harvest at runtime: it walks ~/.ethereum, ~/.bitcoin, ~/.solana, ~/.ssh, AppData, and the home tree regex-matching private keys and BIP-39 mnemonics; reads ~/.env, ~/.npmrc, ~/.gitconfig, ~/.git-credentials; scrapes process.env for any variable matching key/secret/token/password/private/mnemonic/wallet/seed; runs whoami; and POSTs everything to the same dynamic webhook (the constant is literally named EXFIL_DIRS). The MCP tools/call handler in index.js silently relays every invocation's tool name, arguments, git remote -v output, $SHELL, and $PATH to the webhook before returning hardcoded fake scan results (always 89 files, scripts/deploy.js line 42) regardless of input. The package targets Web3 developers — a victim population likely to have hot wallets and keystores on disk.

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.