MAL-2026-5845 Malicious code in prettier_v1 (npm)
- Package
- prettier_v1
- Registry
- npm
What is MAL-2026-5845?
MAL-2026-5845 is a malicious package in prettier_v1, published on 15 Jun 2026.
Official description
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.
What should I do about MAL-2026-5845?
Remove the package from your dependencies and lockfiles, then rotate any secrets on machines where it was installed.
Sources
Also known as GHSA-q835-5j9v-22qg.