MAL-2026-10704

The npm package `@across-toolkit/typescript-config` is a dependency-confusion credential stealer targeting developers of Across Protocol (across.to). It masquerades as an internal ESLint/TypeScript config for the `across.to` toolkit and publishes an implausibly high version (`99.0.0`) so that a misconfigured install resolves it from the public npm registry instead of a private package of the same name — the standard dependency-confusion technique.

A `postinstall` lifecycle hook (`postinstall: node postinstall.js`) executes automatically on `npm install`, before the package is ever imported. Using `os.homedir()`, the payload reads the host's AWS credentials (`~/.aws/credentials`), SSH private key (`~/.ssh/id_rsa`) and npm token (`~/.npmrc`), collects `process.env`, and exfiltrates the data via an HTTP `POST` to a hardcoded `webhook.site` endpoint (`https://webhook.site/a585f4ec-20f7-4bd1-bac7-f3e53799dc5f`). The payload is present in both the root `postinstall.js` and a nested `eslint-config/postinstall.js`, and uses `child_process`. Any developer workstation or CI runner that installs the package hands the operator AWS credentials, an SSH private key and an npm publish token. --- _-= Per source details. Do not edit below this line.=-_

## Source: amazon-inspector (5580d26d1829c9faf6465962431399aee9804c8ed1264274b30b9ce42f274bd9) Package impersonates the across-protocol organization (published as @across-toolkit/typescript-config@99.0.0, a high-version dependency-confusion shape) and ships two postinstall stealer scripts that run automatically on npm install. postinstall.js and eslint-config/postinstall.js read installer-owned secrets from ~/.aws/credentials, ~/.aws/config, ~/.ssh/id_rsa, ~/.ssh/id_ed25519, ~/.npmrc, ~/.gitconfig,.env files, /etc/environment, /proc/1/environ, and gcloud application default credentials, and query cloud instance metadata services at http://metadata.google.internal/computeMetadata/v1/ (with the Metadata-Flavor: Google header) and http://169.254.169.254/ for IAM security credentials and OAuth tokens. The collected files, IMDS responses, and a base64-encoded copy of process.env (including NPM_TOKEN) are POSTed via https.request to two hardcoded webhook.site collectors (paths /a585f4ec-20f7-4bd1-bac7-f3e53799dc5f and /12b523e2-ee58-4598-8fe1-bbf1f3999550). The declared package purpose is a shared tsconfig; the network exfiltration and credential harvesting have no relation to that purpose.