Which versions of dayjscore are malicious?

The following npm versions of dayjscore are flagged malicious: 1.0.0. Treat any of these as compromised.

How do I remediate dayjscore if I installed it?

dayjscore 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 dayjscore — how do I know if it already compromised me?

If dayjscore 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 dayjscore part of a known attack campaign?

Yes — dayjscore is associated with the IN-MAL-2026-010521 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 dayjscore across my projects, lockfiles, and CI pipelines?

Search your lockfiles and build artifacts for dayjscore (version 1.0.0).

Malicious package

dayjscorenpm

Advisory published Jul 14, 2026Updated Jul 14, 2026

dayjscore is a confirmed malicious npm package (MAL-2026-10587) 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 dayjscore (npm)

MAL-2026-10587

Immediate action

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

npm uninstall dayjscore

What this malware does

The package's package.json declares scripts.postinstall = "node.init.js", causing.init.js to run automatically on npm install. The script harvests a hardcoded list of roughly 60 credential-shaped environment variables (including NPM_TOKEN, GITHUB_TOKEN, AWS_ACCESS_KEY_ID/AWS_SECRET_ACCESS_KEY, STRIPE_, DB_PASSWORD, and other cloud/provider tokens), reads files under the installer's home directory (~/.npmrc, ~/.env, ~/config.json, ~/credentials.json), and enumerates ~/.config/* for filenames containing token/cred/secret. It additionally collects host identifiers (os.hostname(), os.platform(), process.cwd(), process.pid, timestamp) and POSTs the resulting JSON via https.request to a hardcoded webhook.cool endpoint (tender-deer-80). The package name mimics the popular dayjs library.

Malicious versions

1 flagged

1.0.0

Indicators of compromise (SHA-256)

bd9b2226f2ebbeccf1bcafbec9c51e2b3f13e3a7712dfc22baa79fbb72393b8a

Detection & response playbook

Credential / info stealer

Find it
Search your lockfiles and build artifacts for dayjscore (version 1.0.0).
If you installed it — respond
dayjscore 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 dayjscore 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. dayjscore 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-2026-010521

References

npmjs.com

Credits

Amazon Inspector · finder

Detect & block this

O3 blocks dayjscore-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

All malware advisories How O3 detects malware Vulnerability database