MalwarePublished 10 Jul 2026Updated 5 Aug 2026

@bcryptln/becryptjs (npm) · Malicious Code

Affects @bcryptln/becryptjsSource GCVE Database

Malicious package : remove @bcryptln/becryptjs and rotate any secrets on hosts that installed it.

Data as of 26 Oct 2026, 15:56 UTC

Classification

Malicious package

Published to npm · OSV MAL-2026-10162

What to do

Remove @bcryptln/becryptjs from every project, lockfile and image that pulls it in. Treat any host that installed it as compromised: rotate the credentials, tokens and keys it could read, from a clean machine.

Affected software

Product	Affected	Fixed in
npm@bcryptln/becryptjs	Affected 3.0.8 – 3.0.11 4 affected builds	Fixed in–

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Description

--- _-= Per source details. Do not edit below this line.=-_ ## Source: amazon-inspector (cb86f48a4b796f17dc1017a92153b88afce1f15690687eaa422162d9dd9f347d) 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.

Impact

Consumers importing @bcryptln/becryptjs as an ESM module risk executing malicious code with full CommonJS module access, potentially allowing arbitrary code execution, filesystem manipulation, network communication, and process spawning. This compromises the security and integrity of applications using this package version.

Defensive guidance

Users should avoid using the affected versions of @bcryptln/becryptjs (=3.0.8, =3.0.10, =3.0.11). Instead, they should switch to the legitimate bcryptjs package or verify package authenticity before use. Monitor vendor advisories for updates or official fixes.

Summary

The package @bcryptln/becryptjs, which mimics the widely-used bcryptjs library, includes a malicious payload appended after legitimate code in its ESM entrypoint (index.js). The payload uses custom string-shuffle decoders to hide the use of the JavaScript Function constructor, which is dynamically created and invoked. It re-exposes CommonJS primitives such as require, module, __dirname, and __filename as globals, allowing the payload to access powerful Node.js modules like fs, child_process, http, and net. The CommonJS/UMD entrypoint (umd/index.js) is a clean copy of the upstream library, making the malicious code only active when the package is imported as an ESM module. This split and obfuscation strategy indicates an intentional supply-chain trojan designed to evade code review and detection.

References

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What to do

Affected software

Description

AI analysisMachine-generated, updated 11 Jul 2026, 09:57 UTC

Technical details

References

Community reviews