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 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

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

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.

Malicious versions

1 flagged

5.0.5

Indicators of compromise (SHA-256)

b8059a1d2db2edb7231b017023f82f6a651585c0ee7120aaebe882cb6407b9e3

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-2026-007259

References

npmjs.com

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