hardhat-capnpm
Advisory published Updated
hardhat-cap is a confirmed malicious npm package (MAL-2026-13616) that typosquats a legitimate package to trick installs (malicious version 2.21.1). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in hardhat-cap (npm)
What this malware does
The package is published as hardhat-cap but its README, LICENSE, index.d.ts, and lib/proto.js / lib/tools.js are a verbatim copy of the pino logger, with author metadata pointing at jsonspack.com. index.js unconditionally does const config = require('./lib/config');, and lib/config.js is a ~4 MB single-line obfuscator.io-transformed module (rotated string array of ~23,931 entries, dual decoders, RC4+base64 string decoding, control-flow flattening) whose top-level IIFE self-invokes at load time. Requiring the package executes this opaque payload on the installer's host at import time; the surrounding pino code is unrelated cover. A logger has no need for a multi-megabyte obfuscated self-decoding blob, and the name/contents mismatch (Hardhat-themed name, pino source, obfuscated third module) is consistent with a typosquat lure that drops arbitrary code execution into consumers on require.
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
TyposquatFind it
Search your lockfiles and build artifacts for hardhat-cap (version 2.21.1).
If you installed it — respond
hardhat-cap is a typosquat — you almost certainly intended a legitimately-named package. Remove hardhat-cap, install the correct package, and rotate any secrets exposed during the install since post-install scripts may have already run.
Did it already run?
If hardhat-cap 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 hardhat-cap-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.