Which versions of bs-bs-core are malicious?

The following npm versions of bs-bs-core are flagged malicious: 35.1.6. Treat any of these as compromised.

How do I remediate bs-bs-core if I installed it?

Remove bs-bs-core from your project and lockfile, then assume any secrets accessible to the build or runtime were exposed: rotate API keys, tokens, and credentials, and audit for unexpected outbound activity or persistence.

I already installed bs-bs-core — how do I know if it already compromised me?

If bs-bs-core 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 bs-bs-core part of a known attack campaign?

Yes — bs-bs-core is associated with the IN-MAL-2026-015247 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 bs-bs-core 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 bs-bs-core (version 35.1.6). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging bs-bs-core across your stack and pipelines.

Malicious package

bs-bs-corenpm

bs-bs-core is a confirmed malicious npm package (MAL-2026-12519) that executes malicious code on install (malicious version 35.1.6). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in bs-bs-core (npm)

MAL-2026-12519

Immediate action

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

npm uninstall bs-bs-core

What this malware does

On require('bs-bs-core'), index.js loads compat.js, which at module load time assembles Cloudflare Workers hostnames from split string arrays (oob-worker.cf99-9b3.workers.dev, oob-worker.cf102-baf.workers.dev, oob-worker.cf103-070.workers.dev, with a DNS TXT-record fallback under *.dl.wel1.ru), downloads a platform-specific executable via https.get, writes it to /tmp as '.cache<hex>' or to Windows TEMP as 'dotnet_diag_<hex>.exe', chmods 755 on Unix, and spawns it detached via /bin/sh -c or cmd. A stamp file named '.analytics_state' is used to gate re-execution. lib/telemetry.js ships a duplicate fetch/base64-decode/chmod/spawn loader framed as an analytics SDK, using string-concatenation obfuscation ('child_'+'process', 'chmod'+'Sync') to hide the child_process API surface. Hostnames, artifact filenames, and API names are string-split to evade static analysis; the downloaded binary is not hash-pinned, not signed, not documented, and not sourced from the package's publisher.

Malicious versions

1 flagged

35.1.6

Indicators of compromise (SHA-256)

3f3619c5623fc30ab616c89c04badd56a5f3de98cba7a625b647ce98921a65f6

Detection & response playbook

Malicious package

Find it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for bs-bs-core (version 35.1.6). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging bs-bs-core across your stack and pipelines.
If you installed it — respond
Remove bs-bs-core from your project and lockfile, then assume any secrets accessible to the build or runtime were exposed: rotate API keys, tokens, and credentials, and audit for unexpected outbound activity or persistence.
Did it already run?
If bs-bs-core 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 bs-bs-core 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. bs-bs-core on npm has been identified as a malicious package (version 35.1.6 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-015247

References

npmjs.com

Credits

Amazon Inspector · finder

Detect & block this

O3 blocks bs-bs-core-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.

Malware detection Runtime egress monitoring

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