MAL-2026-13516 Malicious code in forge-gas-diff (npm)

index.js is advertised as a Foundry gas-report diff utility but on module load / CLI run schedules a setTimeout of 259,200,000 ms (3 days) that calls https.get against https://gist.githubusercontent.com/opensource-crypto/3946ef88aa057c9d10f1a7d80391d164/raw/default.json. The gist is hosted on a GitHub account (opensource-crypto) unrelated to the declared package publisher (danird9). If the fetched JSON contains a c2 field, the value is persisted to ~/.forge-gas-diff.remote for later use. A separate getInstallId() routine writes a per-host UUID to ~/.forge-gas-diff, providing a stable install fingerprint. None of this behavior — outbound network fetch, install-ID generation, remote-config persistence, or a field literally named c2 — has any relationship to the advertised gas-diff functionality and is not documented in the package. The gist is author-mutable, so the content delivered to installers can be changed at any time without republishing the package; the 3-day delay places the fetch well outside typical install-time sandboxing windows. The mechanism is the staging half of a remote-config-driven dropper: a hidden update channel keyed to attacker-editable content on a third-party host, with persistence to a well-known filesystem path on the installer's machine.