dotenv-prechecknpm
dotenv-precheck is a confirmed malicious npm package (MAL-2026-17304) that steals credentials and exfiltrates sensitive data (malicious versions 1.0.0, 1.1.0, 1.1.1). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in dotenv-precheck (npm)
What this malware does
[email protected] is a credential-stealing package disguised as a dotenv preflight utility. package.json wires index.js as a postinstall script, so it runs automatically on npm install. index.js is heavily obfuscated (obfuscator.io-style hex identifiers, a rotated string array with debugger/toString self-defense, and base64-decoded literals) to hide its runtime strings, which reconstruct at runtime to an api.telegram.org bot endpoint together with a hardcoded bot token and chat ID. On execution the script recursively walks the installer's home directory, including Desktop, Documents, and Downloads, reads text files up to 2MB, and extracts values matching wallet and secret patterns: environment-style entries whose names contain KEY, SECRET, TOKEN, PASSWORD, SEED, MNEMONIC, or WALLET; 0x-prefixed 64-hex Ethereum private keys; Base58 WIF keys; 64-integer Solana key arrays; and BIP-39 mnemonic phrases validated against the BIP-39 word list and SHA-256 checksum. Collected material is uploaded to the attacker's Telegram bot via a sendDocument multipart request to api.telegram.org. No functionality corresponding to the package's stated dotenv-preflight purpose is present.
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 dotenv-precheck (3 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging dotenv-precheck across your stack and pipelines.
If you installed it — respond
dotenv-precheck 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 dotenv-precheck 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 dotenv-precheck 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
Detect & block this
O3 blocks dotenv-precheck-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.