Which versions of date-fns-sync are malicious?

The following npm versions of date-fns-sync are flagged malicious: 1.0.0. Treat any of these as compromised.

How do I remediate date-fns-sync if I installed it?

date-fns-sync 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.

I already installed date-fns-sync — how do I know if it already compromised me?

If date-fns-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.

Is date-fns-sync part of a known attack campaign?

Yes — date-fns-sync is associated with the IN-MAL-2026-019140 campaign. Packages in the same campaign often share infrastructure and payloads, so check whether any related packages are also in your dependency tree.

How do I find date-fns-sync across my projects, lockfiles, and CI pipelines?

Search your lockfiles and build artifacts for date-fns-sync (version 1.0.0).

Malicious package

date-fns-syncnpm

Advisory published Aug 29, 2026Updated Aug 29, 2026

date-fns-sync is a confirmed malicious npm package (MAL-2026-15551) that steals credentials and exfiltrates sensitive data (malicious version 1.0.0). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in date-fns-sync (npm)

MAL-2026-15551

Immediate action

Remove the package, then rotate any secrets the build/runtime could reach.

npm uninstall date-fns-sync

What this malware does

package.json declares scripts.postinstall = 'node index.js'. index.js reconstructs a URL from a String.fromCharCode integer array — decoding to https://kongregate-api-config.vercel.app/ — fetches JSON from that endpoint, and passes the returned 'token' field directly to eval(). This executes attacker-controlled JavaScript on the installer's machine at npm install time. The destination is not a package publisher domain, the fetched payload is opaque and mutable, and the URL is deliberately concealed via char-code assembly to evade static analysis. The package's README describes it as a caching module, which does not match the observed behavior.

Malicious versions

1 flagged

1.0.0

Indicators of compromise (SHA-256)

8de9cc36a8817e94d67a46762e62e00a58e17077691ea1b4f649bc1f0d49e967

Detection & response playbook

Credential / info stealer

Find it
Search your lockfiles and build artifacts for date-fns-sync (version 1.0.0).
If you installed it — respond
date-fns-sync 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 date-fns-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

No. date-fns-sync on npm has been identified as a malicious package (version 1.0.0 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-019140

References

npmjs.com

Credits

Amazon Inspector · finder

Detect & block this

O3 blocks date-fns-sync-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.

Malware detection Runtime egress monitoring

Explore

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