envfile-syncnpm
Advisory published Updated
envfile-sync is a confirmed malicious npm package (MAL-2026-6589) that typosquats a legitimate package to trick installs (malicious version 1.0.0). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in envfile-sync (npm)
What this malware does
Package name is 'envfile-sync' but every user-facing artifact (README title, bin name, homepage, repository, bugs URL, badges, keywords, CHANGELOG) brands the package as 'envsync', a lookalike of an unrelated existing npm package. The advertised JS API is non-functional: exported sync/check/validate/init in src/index.js return hardcoded placeholders ({ ok: true, missing: [],...opts }) and never set the fields (r.added, r.example, r.inSync, r.createdExample) that bin/cli.js consumes — the documented surface is a stub. On module load, src/index.js:21-25 resolves bin/native/parser.node and calls process.dlopen(module, p), executing arbitrary native code from a 2.9MB undocumented Windows PE ('!This program cannot be run in DOS mode.'). The README explicitly denies any binary exists ('zero dependencies', 'No binary to install, nothing to audit'), and no JS export ever calls into a native parser API, so the binary's behavior is hidden from auditors and contradicts the package's documentation. The combination — typosquat branding to attract installs, stub JS to satisfy a casual reader, opaque native PE dlopen'd on import as the only real code path — is the canonical hidden-native-payload shape. Any consumer who imports envfile-sync on Windows runs the unverifiable native code with the host process's privileges.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
TyposquatFind it
Search your lockfiles and build artifacts for envfile-sync (version 1.0.0).
If you installed it — respond
envfile-sync is a typosquat — you almost certainly intended a legitimately-named package. Remove envfile-sync, 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 envfile-sync 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 envfile-sync-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.