chai-lognpm
Advisory published Updated
chai-log is a confirmed malicious npm package (MAL-2026-10426) that executes malicious code on install (malicious version 1.1.0). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in chai-log (npm)
What this malware does
[email protected] presents itself as a Mocha reporter mirroring the legitimate eth-gas-reporter project (matching author name, README, and badges), but the exported reporter function reaches only a dropper branch. In index.js, a dead-code guard (var opt = 1; if (!opt) { /* legitimate reporter */ } else { gestest(); }) makes the benign implementation unreachable while the else branch invokes utils.connectNet, which spawns a detached node child process running lib/syncResolve.js. That subprocess fetches JavaScript from https://testlog.edgeone.cool/data.json and executes the response via new Function.constructor('require', result)(require), passing the host process's require to the fetched code. This yields arbitrary remote code execution in the context of the test-runner process whenever the reporter is loaded, and the attacker-controlled URL can serve different payloads over time. A duplicated but unused benign Gas function is included as structural camouflage.
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.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Malicious packageFind it
Search your lockfiles and build artifacts for chai-log (version 1.1.0).
If you installed it — respond
Remove chai-log from your project and lockfile, then assume any secrets accessible to the build or runtime were exposed: rotate API keys, tokens, and credentials, and audit for unexpected outbound activity or persistence.
Did it already run?
If chai-log was installed, its post-install payload may already have run. Removing the package does not undo that — check outbound connections and credential use from the install window onward.
Frequently asked questions
Campaign
References
Credits
- Amazon Inspector · finder
Detect & block this
O3 blocks chai-log-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the malicious outbound activity and severs the channel.