Which versions of jest-formatter are malicious?

The following npm versions of jest-formatter are flagged malicious: 1.0.0. Treat any of these as compromised.

How do I remediate jest-formatter if I installed it?

jest-formatter 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 jest-formatter — how do I know if it already compromised me?

If jest-formatter 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 jest-formatter part of a known attack campaign?

Yes — jest-formatter is associated with the IN-MAL-2026-010208 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 jest-formatter 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 jest-formatter (version 1.0.0). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging jest-formatter across your stack and pipelines.

Malicious package

jest-formatternpm

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

MAL-2026-10436

Immediate action

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

npm uninstall jest-formatter

What this malware does

The package [email protected] presents itself as a Jest test output formatter but its lib/collect.js imports child_process and invokes execSync with bash and zsh at lines 205 and 221. The 'collect' module name combined with shell execution via multiple shells is consistent with harvesting installer-side data (shell history, credentials, environment) from Unix hosts. The behavior does not match the advertised purpose of formatting test output, and the traced content matched patterns associated with credential/data collection payloads. Concrete shell-exec sinks in a module named 'collect' inside a package with no legitimate need for bash/zsh invocation indicate an active data-collection payload rather than a formatter library.

Malicious versions

1 flagged

1.0.0

Indicators of compromise (SHA-256)

af1f270f7df9ee4f9088044964921e1b085b809ddb1d696e652326c58e5c0aba

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

Campaign

IN-MAL-2026-010208

References

npmjs.com

Credits

Amazon Inspector · finder

Detect & block this

O3 blocks jest-formatter-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