MAL-2026-6791 Malicious code in npm-show-date-proof-strings (npm)

The package's postinstall.js runs on every npm install and collects the installer's username (via whoami and os.userInfo()), hostname (os.hostname()), platform (process.platform), and Node version, then transmits them as query parameters via https.get() to a hardcoded endpoint at https://testnpm.byte.eyes.sh/npm-proof. The destination is author-controlled and undocumented; the installer has no opportunity to opt out. The package name ("npm-show-date-proof-strings") and an embedded NONCE string ("proof-2026-change-this-random-string") indicate this is a proof-of-execution beacon, but regardless of framing, it is unconsented host-identifier collection on install with no legitimate installer-facing purpose.

The OpenSSF Package Analysis project identified 'npm-show-date-proof-strings' @ 1.0.3 (npm) as malicious.

It is considered malicious because:

• The package executes one or more commands associated with malicious behavior.