Which versions of prettier_v1 are malicious?

The following npm versions of prettier_v1 are flagged malicious: 3.8.4, 3.8.5. Treat any of these as compromised.

How do I remediate prettier_v1 if I installed it?

prettier_v1 is a typosquat — you almost certainly intended a legitimately-named package. Remove prettier_v1, install the correct package, and rotate any secrets exposed during the install since post-install scripts may have already run.

I already installed prettier_v1 — how do I know if it already compromised me?

If prettier_v1 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 prettier_v1 part of a known attack campaign?

Yes — prettier_v1 is associated with the GHSA-q835-5j9v-22qg, IN-MAL-2026-008989, IN-MAL-2026-009438, RLMA-2026-05596 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 prettier_v1 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 prettier_v1 (2 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging prettier_v1 across your stack and pipelines.

Malicious package

prettier_v1npm

prettier_v1 is a confirmed malicious npm package (MAL-2026-5845) that typosquats a legitimate package to trick installs (malicious versions 3.8.4, 3.8.5). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in prettier_v1 (npm)

MAL-2026-5845

Immediate action

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

npm uninstall prettier_v1

What this malware does

Package name 'prettier_v1' closely resembles the widely-used 'prettier' formatter package, a classic typosquat naming pattern. The file lib/mirror.js contains a Buffer.from(..., 'base64').toString('utf8') decode primitive at line 16, which is commonly used to obscure embedded payloads. Tracing of the decoded content and its downstream use (whether it is passed to eval/exec, written to disk, or executed) was not completed, so the actual installer-side impact has not been confirmed. The combination of a typosquat-shaped name plus a base64 decode in a file named 'mirror.js' warrants human review before this package is allowed into installer environments.

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

2 flagged

3.8.43.8.5

Indicators of compromise (SHA-256)

ea8303f0cea5f415b8a0ba74e959d0501fcb3142ee9320fa50668674c578e4bb

1ae1d77d25db3af85295c48a446f6c0f2f65252ea2483c45ce81df12c75b1fcb

e007377ee649874106f24fb14c3bf26aa17187d815d9bbea64b87e6a02c10edf

250db4bc59de3c3be8f6a8c9eb787cebbf59e29804bd6138b7cda43d287b9855

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 prettier_v1 (2 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging prettier_v1 across your stack and pipelines.
If you installed it — respond
prettier_v1 is a typosquat — you almost certainly intended a legitimately-named package. Remove prettier_v1, 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 prettier_v1 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 prettier_v1 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. prettier_v1 on npm has been identified as a malicious package (versions 3.8.4, 3.8.5 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

GHSA-q835-5j9v-22qgIN-MAL-2026-008989IN-MAL-2026-009438RLMA-2026-05596

References

Credits

Amazon Inspector · finder
ReversingLabs · finder

Detect & block this

O3 blocks prettier_v1-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

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