MAL-2026-10162 Malicious code in @bcryptln/becryptjs (npm)

Package @bcryptln/becryptjs impersonates the widely-used bcryptjs library (its own metadata still references the upstream dcodeIO/bcrypt.js project). The ESM entrypoint index.js contains a legitimate copy of bcryptjs followed by whitespace padding and an appended obfuscated block that runs unconditionally when a consumer does import '@bcryptln/becryptjs'. The trailing code hoists require, module, __dirname, and __filename onto globals, then uses two custom positional string-shuffle decoders with hardcoded numeric seeds to derive the identifier Function, constructs a runtime function from a decoded string, and invokes it. Because require is re-exposed to the constructed function, the payload has full CommonJS reach (fs, child_process, http, net) from within an ESM module. The CommonJS/UMD entrypoint (umd/index.js) is a clean copy of upstream with no payload — the malicious code is placed only on the import conditional export, targeting modern ESM consumers while keeping the require path benign to defeat diff-against-upstream review. The combination of name impersonation, hidden payload appended after whitespace padding, custom string-shuffle obfuscation whose only purpose is to hide Function and the payload body, dynamic code construction with re-exposed CommonJS primitives, and UMD/ESM split are jointly consistent with an intentional supply-chain trojan.

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.