chain-key-validatornpm
Malicious code in chain-key-validator (npm) Remove it immediately and rotate any exposed credentials.
What this malware does
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”).
chain-key-validator presents itself as a blockchain key validation MCP server. The malicious postinstall hook was injected in version 0.2.3 — prior version 0.2.1 (published 2026-05-19) contained no hook, confirming an intentional posture-degradation update. The MCP tool verify_key_format explicitly solicits “Private key or key material to validate” and benchmark_key_strength solicits “Key material to benchmark”, then exfiltrates the supplied values to the C2. scanner.js is confirmed byte-for-byte identical to the version in defi-env-auditor.
Package poses as a 'Cryptographic Security Foundation' MCP tool that validates blockchain private keys, but is a credential harvester and wallet drainer. (1) package.json scripts.postinstall is an inline node -e that runs on npm install and reads ~/.ssh, ~/.ethereum, ~/.bitcoin, ~/.env, ~/.bash_history, ~/.zsh_history, /.git-credentials, captures hostname/user/cwd, and POSTs them to a webhook resolved from https://ddjidd564.github.io/defi-security-best-practices/config.json. (2) scanner.js (loaded from index.js) recursively walks the home directory and platform keystore paths (/.ethereum, ~/.solana, AppData, Library/Application Support), regex-matches private keys and BIP-39 mnemonics, reads ~/.npmrc, ~/.gitconfig, ~/.git-credentials, shell history, and environment variables matching key/secret/token/password/mnemonic/seed, then POSTs the harvest to the same dynamically-resolved webhook. (3) The MCP tools/call handler in index.js unconditionally forwards the caller's arguments — including the private key the user is asked to 'validate' — to the attacker webhook before returning a fake validation result, making the package's advertised function a silent relay of user-supplied secrets. The webhook URL is fetched at runtime from a github.io config so the attacker can rotate exfil endpoints without republishing.
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.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Credential / info stealerFind it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for chain-key-validator (14 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging chain-key-validator across your stack and pipelines.
If you installed it — respond
chain-key-validator is built to steal secrets, so assume every credential the build or runtime could read is compromised. Remove it from your project and lockfile, then rotate ALL exposed secrets — npm/registry tokens, cloud keys, CI/CD secrets, SSH keys, and any .env values — from a known-clean machine. Audit logs for unauthorized use of those credentials.
Did it already run?
If chain-key-validator was ever installed, its post-install/runtime payload may have already executed. O3's L7 egress monitoring and runtime eBPF sensors detect the credential exfiltration or command-and-control callback after install and block the malicious outbound channel, so you catch and contain the actual compromise — not just the presence of the package.
How O3 protects you
O3 blocks chain-key-validator before install through its supply-chain scanner, and if it has already run, detects and severs the exfiltration or C2 callback at runtime through L7 egress monitoring and eBPF.
Frequently asked questions
Campaign
References
Credits
- Amazon Inspector · finder
- SafeDep · finder
Detect & block this
O3 blocks chain-key-validator-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.