MAL-2026-5842 Malicious code in browserslist-db-sync (npm)

lib/mirror.js line 13 contains a Buffer.from(…, "base64").toString("utf8") pattern. This decoding primitive is common in benign code (parsing JWTs, decoding configuration, handling embedded assets) but is also used to obfuscate hardcoded URLs, payloads, or credentials. Contextual tracing of how the decoded value is used did not complete, so intent cannot be determined from the available evidence. The package name suggests a browserslist database mirror/sync utility; a human reviewer should confirm whether the decoded data is benign content (configuration, mirror URL) or hides attacker-controlled strings or executable payload.

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.