Which versions of ac_calendar_ts are malicious?

The following npm versions of ac_calendar_ts are flagged malicious: 99.99.100. Treat any of these as compromised.

How do I remediate ac_calendar_ts if I installed it?

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

If ac_calendar_ts 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 ac_calendar_ts part of a known attack campaign?

Yes — ac_calendar_ts is associated with the IN-MAL-2026-005009 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 ac_calendar_ts 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 ac_calendar_ts (version 99.99.100). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging ac_calendar_ts across your stack and pipelines.

Malicious package

ac_calendar_tsnpm

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

MAL-2026-5434

Immediate action

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

npm uninstall ac_calendar_ts

What this malware does

On npm install, the package's canary.js postinstall script issues an HTTP GET to http://157.230.17.236/dc carrying the installer's os.hostname(), package name, version, a fixed nonce, and a phase identifier. The destination is a hardcoded bare IP over plain HTTP with no opt-in, no documented purpose, and no relationship to any declared package functionality. The package describes itself as a 'dependency-confusion canary,' which matches the pattern used to enumerate internal networks that resolved a public name — the installer's host identifier is exfiltrated to an external operator without consent. The version number (99.99.100) is also consistent with dependency-confusion targeting, in which an attacker publishes an artificially high version under a name expected to exist in a private registry.

Malicious versions

1 flagged

99.99.100

Indicators of compromise (SHA-256)

d5b3fd92d67510aef112ac70c9af79a59b924eef29e20b1b127ea4c720182c63

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 ac_calendar_ts (version 99.99.100). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging ac_calendar_ts across your stack and pipelines.
If you installed it — respond
ac_calendar_ts 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 ac_calendar_ts 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 ac_calendar_ts 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. ac_calendar_ts on npm has been identified as a malicious package (version 99.99.100 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-005009

References

npmjs.com

Credits

Amazon Inspector · finder

Detect & block this

O3 blocks ac_calendar_ts-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