gas-diff-corenpm
gas-diff-core is a confirmed malicious npm package (MAL-2026-13517) that opens a backdoor for remote access (malicious version 1.0.0). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in gas-diff-core (npm)
What this malware does
On require(), index.js runs an IIFE that persists an install timestamp and UUID under ~/.forge/gas-diff.json. After 72 hours have elapsed since first install, and at most once per 24 hours thereafter, it fetches JSON from https://gist.githubusercontent.com/opensource-crypto/3946ef88aa057c9d10f1a7d80391d164/raw/default.json and, when the response contains a c2 key, writes that value to a hidden ~/.forge/.remote file. The gist is hosted under an anonymous GitHub account unrelated to the package publisher and is mutable — its contents can be swapped by the gist owner at any time to stage arbitrary command-and-control configuration on installer hosts. The 72-hour dormancy window suppresses the network activity in CI, install-time sandboxes, and short-lived analysis environments, and the destination field is literally named c2 and stored in a dotfile named .remote.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Backdoor / remote accessFind it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for gas-diff-core (version 1.0.0). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging gas-diff-core across your stack and pipelines.
If you installed it — respond
gas-diff-core establishes remote access, so treat any host that installed it as fully compromised. Isolate the machine, remove the package, rotate all credentials it could reach, and rebuild from a trusted image rather than cleaning in place — a backdoor may have planted additional persistence.
Did it already run?
If gas-diff-core was ever installed, its post-install/runtime payload may have already executed. O3's L7 egress monitoring and runtime eBPF sensors detect the credential exfiltration or command-and-control callback after install and block the malicious outbound channel, so you catch and contain the actual compromise — not just the presence of the package.
How O3 protects you
O3 blocks gas-diff-core before install through its supply-chain scanner, and if it has already run, detects and severs the exfiltration or C2 callback at runtime through L7 egress monitoring and eBPF.
Frequently asked questions
Campaign
References
Credits
- Amazon Inspector · finder
Detect & block this
O3 blocks gas-diff-core-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the C2 callback and severs the channel.