@gusmano/reextnpm
Malicious code in @gusmano/reext (npm) Remove it immediately and rotate any exposed credentials.
What this malware does
The npm preinstall lifecycle script (dist/scripts/preinstall.js, wired via package.json "preinstall": "node./dist/scripts/preinstall.js") reads the installer's ~/.gitconfig via iniparser.parseSync(home_dir+'/.gitconfig') and the OS username via os.userInfo().username, then issues an HTTPS GET to the hardcoded endpoint https://2tak.l.serverhost.name:1962/mobile/reext with osname, gitname, and gitemail supplied as query parameters. The code explicitly branches on if (osname === 'xmarcgusmano') { server = 'http://localhost:1962' } else { server = 'https://2tak.l.serverhost.name:1962' }, confirming that the remote-host path fires for every installer that is not the author's own machine — a deliberate exfiltration path gated by the author's own username. The destination is not a documented vendor endpoint; it is an author-controlled third-party host the installer did not opt into. Separately, dist/scripts/postinstall.js resolves path.resolve(__dirname, '../../package.json') (the consuming project's own package.json relative to node_modules/@gusmano/reext/dist/scripts/) and rewrites it, deleting scripts.dev/build/test/watch/coverage, the entire scripts key, eslintConfig, devDependencies, and dependencies, then rm -rf's several dist subfolders — destructive, unauthorized mutation of the installer's project files. The combination (silent install-time exfiltration of personal identity data to an author-controlled host plus destructive rewrite of the consumer's manifest) is unambiguously harmful to installers.
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 @gusmano/reext (34 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging @gusmano/reext across your stack and pipelines.
If you installed it — respond
@gusmano/reext 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 @gusmano/reext 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 @gusmano/reext 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 @gusmano/reext-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.