Which versions of viem-js are malicious?

The following npm versions of viem-js are flagged malicious: 1.0.0, 1.0.2, 1.0.4. Treat any of these as compromised.

How do I remediate viem-js if I installed it?

Remove viem-js 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 viem-js — how do I know if it already compromised me?

If viem-js 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 viem-js part of a known attack campaign?

Yes — viem-js is associated with the GHSA-257w-wr4p-5rxp, RLMA-2026-01641 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 viem-js 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 viem-js (3 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging viem-js across your stack and pipelines.

Malicious package

viem-jsnpm

Malicious code in viem-js (npm) Remove it immediately and rotate any exposed credentials.

MAL-2026-334

Immediate action

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

npm uninstall viem-js

What this malware does

The package viem-js was found to contain malicious code.

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

3 flagged

1.0.01.0.21.0.4

Indicators of compromise (SHA-256)

7b2687f596cd8f76eec0d498e10a1f632b4ae06acd052210c214ee332feddb9d

73dca89de6152d63a64cab3a25d8444853cfdd2502260ea1d2b33f055d4adaec

1a8fe089197ca893ee77a940733ab90e514451fd20e2c1c2b81bed8a7c82c2c4

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 viem-js (3 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging viem-js across your stack and pipelines.
If you installed it — respond
Remove viem-js 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 viem-js 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 viem-js 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. viem-js on npm has been identified as a malicious package (versions 1.0.0, 1.0.2, 1.0.4 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

GHSA-257w-wr4p-5rxpRLMA-2026-01641

References

Credits

Amazon Inspector · finder
ReversingLabs · finder

Detect & block this

O3 blocks viem-js-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