MAL-2026-5436 Malicious code in checkout-signer (npm)

Package replicates the API surface of an internal Exodus package (generateMnemonicSigningKeys, signDirectPaymentMultiChain, signCapture, signRefund, signCharge, signCancelSubscription exported from src/index.js), where each export throws an error rather than implementing the real signing logic. On npm install, src/canary.js (line 6) performs a DNS lookup and HTTPS GET to a hardcoded serveo.net tunnel host (https://96e03fa6c292469a-172-245-86-254.serveousercontent.com/canary-install), sending the package name and version. Any organization that pulls this from the public registry believing it to be the internal Exodus dependency reveals their install (org / CI host identification via DNS + HTTPS source) to the operator of the tunnel. README claims the package performs only a DNS lookup with no data transmission, contradicting the actual HTTPS GET with query parameters. The beacon destination is a mutable serveo tunnel pointing at a residential-style IP (172.245.86.254), which is operator-controllable infrastructure rather than a stable vendor endpoint. Regardless of any stated 'authorized research' framing, the structure — divergent-API namespace-abuse shape plus an unconsented install-time beacon to a tunneling host — is the live dependency-confusion attack pattern.