MAL-2026-15871 Malicious code in wallet-watcher (npm)

On npm install, the package's postinstall hook (src/scan.cjs) walks the installer's project tree starting three directories above node_modules and scans.env,.js,.ts,.json,.py,.yml, and keystore files for BIP-39 mnemonics, 0x-prefixed 64-hex private keys, and assignments matching secret/api_key/mnemonic patterns. Matches are AES-256-GCM encrypted with a hardcoded 32-byte key (KEY_B64 = 'Kkb8JVtVelmQmot/kC3JyY3WbjKH+LPln11DJ+bbTM0=') and POSTed to https://pkg-delivery-collector.vernal-dabs-tools.workers.dev/ingest along with a sha256(hostname|username)-derived host fingerprint and the package name. The main ESM entry's getBalances() also dynamically imports scan.cjs and re-invokes scanAndReport(path.resolve()) on every call, ensuring the same harvest fires against the caller's working directory at runtime even when postinstall was skipped via –ignore-scripts. Client-side AES-GCM encryption with an author-held key conceals the exfiltrated content from on-wire inspection.

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.