npm-sandbox-research-8b2fnpm
Advisory published Updated
npm-sandbox-research-8b2f is a confirmed malicious npm package (MAL-2026-5758) that opens a backdoor for remote access (malicious version 1.0.0). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in npm-sandbox-research-8b2f (npm)
What this malware does
On install, package.json runs postinstall: node run.js, which loads beacon scripts (beacon8.js, beacon_linux.js) that import child_process, os, and http, gather host identity (output of whoami, os.hostname(), os.platform()), and POST the collected data to a hardcoded HTTP endpoint via http.request(...). This fires automatically on npm install, providing attacker-controlled reconnaissance of every installer host with no user interaction. The behavior — privileged shell command execution, host identity collection, and outbound HTTP POST from a postinstall hook — matches the active-attack reconnaissance/beacon fingerprint.
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
Backdoor / remote accessFind it
Search your lockfiles and build artifacts for npm-sandbox-research-8b2f (version 1.0.0).
If you installed it — respond
npm-sandbox-research-8b2f establishes remote access, so treat any host that installed it as fully compromised. Isolate the machine, remove the package, rotate all credentials it could reach, and rebuild from a trusted image rather than cleaning in place — a backdoor may have planted additional persistence.
Did it already run?
If npm-sandbox-research-8b2f 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 npm-sandbox-research-8b2f-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the C2 callback and severs the channel.