Which versions of @ensdomains/hardhat-chai-matchers-viem are malicious?

The following npm versions of @ensdomains/hardhat-chai-matchers-viem are flagged malicious: 0.1.15. Treat any of these as compromised.

How do I remediate @ensdomains/hardhat-chai-matchers-viem if I installed it?

@ensdomains/hardhat-chai-matchers-viem is built to steal secrets, so assume every credential the build or runtime could read is compromised. Remove it from your project and lockfile, then rotate ALL exposed secrets — npm/registry tokens, cloud keys, CI/CD secrets, SSH keys, and any .env values — from a known-clean machine. Audit logs for unauthorized use of those credentials.

I already installed @ensdomains/hardhat-chai-matchers-viem — how do I know if it already compromised me?

If @ensdomains/hardhat-chai-matchers-viem 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 @ensdomains/hardhat-chai-matchers-viem part of a known attack campaign?

Yes — @ensdomains/hardhat-chai-matchers-viem is associated with the GHSA-h5cf-hh6x-vm87 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 @ensdomains/hardhat-chai-matchers-viem 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 @ensdomains/hardhat-chai-matchers-viem (version 0.1.15). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging @ensdomains/hardhat-chai-matchers-viem across your stack and pipelines.

Malicious package

@ensdomains/hardhat-chai-matchers-viemnpm

Malicious code in @ensdomains/hardhat-chai-matchers-viem (npm) Remove it immediately and rotate any exposed credentials.

MAL-2025-190733

Immediate action

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

npm uninstall @ensdomains/hardhat-chai-matchers-viem

What this malware does

The package @ensdomains/hardhat-chai-matchers-viem 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.

This package was compromised by the Sha1-Hulud: The Second Coming NPM worm. The malicious payload steals tokens and credentials and publishes them to GitHub. The worm will propogate itself to NPM packages the user owns and establish persistence is a GitHub action. The package may also destroy the user's home directory.

Malicious versions

1 flagged

0.1.15

Indicators of compromise (SHA-256)

0f8a94adcd4487bc48ba37e0e3ae28b3cc9369ec9522f2d5cfd820eed372361b

1999f51becf9c74a78a05fda5c53906b196ac72e115d0555b88ff2dc855adca5

fdd57c43d4f2eee83999495a3260acc12b117a6b4f875c2b5f0267c51340a20c

bfe9613b2a060b5e198498a1ec524cbf8e1fbaf04cb5902d7d765edf6ac2284e

Detection & response playbook

Credential / info stealer

Find it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for @ensdomains/hardhat-chai-matchers-viem (version 0.1.15). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging @ensdomains/hardhat-chai-matchers-viem across your stack and pipelines.
If you installed it — respond
@ensdomains/hardhat-chai-matchers-viem is built to steal secrets, so assume every credential the build or runtime could read is compromised. Remove it from your project and lockfile, then rotate ALL exposed secrets — npm/registry tokens, cloud keys, CI/CD secrets, SSH keys, and any .env values — from a known-clean machine. Audit logs for unauthorized use of those credentials.
Did it already run?
If @ensdomains/hardhat-chai-matchers-viem 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 @ensdomains/hardhat-chai-matchers-viem 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. @ensdomains/hardhat-chai-matchers-viem on npm has been identified as a malicious package (version 0.1.15 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

GHSA-h5cf-hh6x-vm87

References

Credits

Amazon Inspector · finder

Detect & block this

O3 blocks @ensdomains/hardhat-chai-matchers-viem-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.

Malware detection Runtime egress monitoring