helmet-pronpm
Advisory published Updated
helmet-pro is a confirmed malicious npm package (MAL-2026-13401) that typosquats a legitimate package to trick installs (malicious version 10.0.4). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in helmet-pro (npm)
What this malware does
[email protected] is a typosquat of the popular helmet HTTP-header middleware. Its package.json postinstall hook runs lib/utils/index.js, which spawns lib/utils/smtp-connection/index.js as a detached child with all stdio silenced. That file is string-array/hex-name obfuscated and, when decoded, performs an axios.get against https://api.jsonbin.io/v3/b/6a719632da38895dfeb7128d and passes the returned record.message to new Function('require',...)(require). The result is arbitrary remote code execution on the installer's machine at npm install time, with require available to the fetched payload. The jsonbin.io record is attacker-mutable, so the executed payload can change at any time without republishing the package. The package also masquerades in metadata/comments as a nodemailer-adjacent SMTP module to disguise the dropper.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
TyposquatFind it
Search your lockfiles and build artifacts for helmet-pro (version 10.0.4).
If you installed it — respond
helmet-pro is a typosquat — you almost certainly intended a legitimately-named package. Remove helmet-pro, install the correct package, and rotate any secrets exposed during the install since post-install scripts may have already run.
Did it already run?
If helmet-pro was installed, its post-install payload may already have run. Removing the package does not undo that — check outbound connections and credential use from the install window onward.
Frequently asked questions
Campaign
References
Credits
- Amazon Inspector · finder
Detect & block this
O3 blocks helmet-pro-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the malicious outbound activity and severs the channel.