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 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.

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?

Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for dayjscore (version 1.0.0). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging dayjscore across your stack and pipelines.

Malicious package

dayjscorenpm

Malicious code in dayjscore (npm) Remove it immediately and rotate any exposed credentials.

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
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for dayjscore (version 1.0.0). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging dayjscore across your stack and pipelines.
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 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 dayjscore 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

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