MAL-2026-5837 Malicious code in postcss-minify-selector (npm)

Package is published as postcss-minify-selector (singular) but its internal postcss plugin identifier is postcss-minify-selectors (plural) — the canonical name of the legitimate cssnano plugin. The published name is a one-character deletion from that target. The first executable line of src/index.js is a side-effect-only require('postcss-minify-selector-parser/cjs-runner') whose return value is discarded and which is not referenced anywhere else in the file; the plugin's actual selector-parsing functionality uses a different subpath, require('postcss-minify-selector-parser/selector-parser'), imported separately at line 6. The sibling dependency postcss-minify-selector-parser (declared as ^2.0.2 in package.json) is itself a typosquat-shaped name of the well-known postcss-selector-parser. The combination — typosquat lure name, plural-vs-singular mismatch with the real cssnano plugin, declared dependency on a second typosquat-shaped package, and an unconditional side-effect require of an otherwise-unused subpath of that dependency at the top of the main entry — is the canonical lure-plus-dropper shape: any consumer that require()s this package will silently load and execute whatever the cjs-runner module body of the sibling typosquat does at require time.

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.