Which versions of ts-arithmetic-helper are malicious?

The following npm versions of ts-arithmetic-helper are flagged malicious: 3.7.2. Treat any of these as compromised.

How do I remediate ts-arithmetic-helper if I installed it?

ts-arithmetic-helper is a typosquat — you almost certainly intended a legitimately-named package. Remove ts-arithmetic-helper, install the correct package, and rotate any secrets exposed during the install since post-install scripts may have already run.

I already installed ts-arithmetic-helper — how do I know if it already compromised me?

If ts-arithmetic-helper 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 ts-arithmetic-helper part of a known attack campaign?

Yes — ts-arithmetic-helper is associated with the IN-MAL-2026-007262, GHSA-94cr-ccj8-78g6 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 ts-arithmetic-helper 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 ts-arithmetic-helper (version 3.7.2). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging ts-arithmetic-helper across your stack and pipelines.

Malicious package

ts-arithmetic-helpernpm

Malicious code in ts-arithmetic-helper (npm) Remove it immediately and rotate any exposed credentials.

MAL-2026-6315

Immediate action

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

npm uninstall ts-arithmetic-helper

What this malware does

[email protected] ships source files that copy the big.js v7.0.1 library verbatim (preserving Michael Mclaughlin's copyright banner and the full big.js API) but inserts a hidden require('parket-flow') call between the P.minus and P.mod method definitions in both big.js and big.mjs. The require is wrapped in an empty try/catch and immediately invokes doc.from_str() with errors silently swallowed. Real big.js has zero runtime dependencies and never executes this code. parket-flow is declared as a runtime dependency in package.json ("parket-flow": "^3.0.2"), so any installer that requires or imports this module pulls parket-flow into the dependency tree and executes its code at module load time. The placement mid-file (rather than at the top), the error suppression, and the impersonation of a popular library are consistent with a deliberate dependency-chain dropper rather than a legitimate fork. The malicious payload is delivered through the smuggled transitive — installers believing they have a big.js-compatible math helper instead silently load and execute parket-flow.

Any computer that has this package installed or running should be considered fully compromised. All secrets and keys stored on that computer should be rotated immediately from a different computer. The package should be removed, but as full control of the computer may have been given to an outside entity, there is no guarantee that removing the package will remove all malicious software resulting from installing it.

Malicious versions

1 flagged

3.7.2

Indicators of compromise (SHA-256)

4712d3f1a81541e2b3143f89974200358301b0a9831c3187875adc1fbe82bfbe

871fa8ae5d633320ff6ef6e02018051f3482676ba15bfb61680de1389bc4ce0f

Detection & response playbook

Typosquat

Find it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for ts-arithmetic-helper (version 3.7.2). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging ts-arithmetic-helper across your stack and pipelines.
If you installed it — respond
ts-arithmetic-helper is a typosquat — you almost certainly intended a legitimately-named package. Remove ts-arithmetic-helper, install the correct package, and rotate any secrets exposed during the install since post-install scripts may have already run.
Did it already run?
If ts-arithmetic-helper 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 ts-arithmetic-helper 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. ts-arithmetic-helper on npm has been identified as a malicious package (version 3.7.2 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-007262GHSA-94cr-ccj8-78g6

References

Credits

Amazon Inspector · finder

Detect & block this

O3 blocks ts-arithmetic-helper-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