@welcome-onboarding-web/mobile-focus-account-beta-mergingnpm
Advisory published Updated
@welcome-onboarding-web/mobile-focus-account-beta-merging is a confirmed malicious npm package (MAL-2026-5923) that executes malicious code on install (malicious version 4.28.7). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in @welcome-onboarding-web/mobile-focus-account-beta-merging (npm)
What this malware does
scripts/postinstall.js is heavily obfuscated (obfuscator.io with rotated base64-RC4 string array and a self-defending regex tamper check that infinite-loops on debuggers/beautifiers). On npm install, the postinstall hook walks up from process.cwd() to fingerprint the parent project, selects a remote URL based on os.platform() (linux/darwin/win32), fetches the response body via http(s).get into a Buffer, writes it to a file under os.tmpdir(), then spawns it via child_process.spawn(process.execPath, [tmpFile], {detached: true, stdio: 'ignore', env: {...process.env,...}}).unref() — a classic detached install-time remote code dropper that ships the installer's full environment to the spawned process. The package's library surface is non-functional (declared main dist/index.js only re-exports ../src/index.js, but no src/ directory ships in the tarball), and the publisher identity (welcome-onboarding-web.io with fabricated jira/docs/github/npm subdomains) does not correspond to a real organization. The package's only effect on install is execution of the obfuscated dropper.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Malicious packageFind it
Search your lockfiles and build artifacts for @welcome-onboarding-web/mobile-focus-account-beta-merging (version 4.28.7).
If you installed it — respond
Remove @welcome-onboarding-web/mobile-focus-account-beta-merging 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 @welcome-onboarding-web/mobile-focus-account-beta-merging 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 @welcome-onboarding-web/mobile-focus-account-beta-merging-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.