@syncraft-labs/reactnpm

dist/index.js (the ESM entry resolved by default by modern bundlers such as Vite, Next.js, and Webpack) contains a heavily obfuscated block using obfuscator.io-style identifiers, a rotated ~300-entry string array, and a decoder wrapper injected inside the useEffect body of the useSync hook. The block captures globalThis.r=require and globalThis.m=module, then uses http/https and zlib (createInflate/createBrotli) to fetch data from Ethereum RPC endpoints (h.drpc.org, 1rpc.io/eth), Blockscout, and Etherscan for a hardcoded contract address (0xa322E5f3...), reconstructs code from the on-chain bytes, and executes it with require access. This is the EtherHiding pattern: the on-chain contract is mutable, so operators of that contract can deliver arbitrary JavaScript to any consumer that renders a component using useSync, achieving remote code execution in Node build/SSR contexts and in the browser bundle of downstream applications. The obfuscated blob is absent from dist/index.cjs and from the TypeScript sources referenced by dist/index.js.map, indicating the ESM artifact was tampered after build.

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.