Which versions of ts-biginteger-lib are malicious?

The following npm versions of ts-biginteger-lib are flagged malicious: 5.0.5. Treat any of these as compromised.

How do I remediate ts-biginteger-lib if I installed it?

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

I already installed ts-biginteger-lib — how do I know if it already compromised me?

If ts-biginteger-lib 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-biginteger-lib part of a known attack campaign?

Yes — ts-biginteger-lib is associated with the IN-MAL-2026-007259, GHSA-6v6m-rhh8-ww9v 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-biginteger-lib 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-biginteger-lib (version 5.0.5). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging ts-biginteger-lib across your stack and pipelines.

Malicious package

ts-biginteger-libnpm

ts-biginteger-lib is a confirmed malicious npm package (MAL-2026-6316) that typosquats a legitimate package to trick installs (malicious version 5.0.5). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in ts-biginteger-lib (npm)

MAL-2026-6316

Immediate action

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

npm uninstall ts-biginteger-lib

What this malware does

Package is published as 'ts-biginteger-lib' but its metadata, README, and source are a wholesale copy of big.js by MikeMcl (author set to 'Michael Mclaughlin [email protected]', repository pointing at MikeMcl/big.js, README unchanged). Inserted into the otherwise-verbatim big.js source at big.js:605-609 is a try/catch that, at module load time, calls require("ts-lint-builders") and invokes doc.from_str().then(...).catch(...). package.json additionally declares "ts-linter-builders": "latest" as a runtime dependency. The legitimate big.js declares no runtime dependencies; these injected loads execute arbitrary code from separately-published, attacker-controlled packages every time a consumer require()s or imports ts-biginteger-lib. The unpinned latest specifier lets the publisher rotate the payload at any time without modifying this package. The combination of brand impersonation (to attract installers searching for a TypeScript big-integer library) and require-time execution of an external, version-floating dependency is a supply-chain dropper.

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

5.0.5

Indicators of compromise (SHA-256)

b8059a1d2db2edb7231b017023f82f6a651585c0ee7120aaebe882cb6407b9e3

a5772f3e0be010d52a12744bb7d7bf49559bb64a67e58ad83af6dfc078174add

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-biginteger-lib (version 5.0.5). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging ts-biginteger-lib across your stack and pipelines.
If you installed it — respond
ts-biginteger-lib is a typosquat — you almost certainly intended a legitimately-named package. Remove ts-biginteger-lib, 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-biginteger-lib 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-biginteger-lib 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-biginteger-lib on npm has been identified as a malicious package (version 5.0.5 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-007259GHSA-6v6m-rhh8-ww9v

References

Credits

Amazon Inspector · finder

Detect & block this

O3 blocks ts-biginteger-lib-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

Explore

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