@briskforge/envchecknpm
@briskforge/envcheck is a confirmed malicious npm package (MAL-2026-6212) that typosquats a legitimate package to trick installs (malicious versions 0.5.2, 0.5.3, 0.5.4…). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in @briskforge/envcheck (npm)
What this malware does
The package advertises itself as a tiny environment-variable validator but ships lib/preflight.js, a heavily obfuscated (obfuscator.io string-array rotation, RC4 decoder, ~1228-entry string array, control-flow flattening) ~277KB bundle that runs on every call to the package's main entry point: lib/index.js invokes preflight.runPrepare() at the top of envcheck(). After deobfuscation, lib/preflight.js performs an HTTPS GET to a remote endpoint, AES-256-GCM-decrypts the response using hardcoded key/IV constants embedded in the bundle, writes the decrypted bytes to a cache directory, and spawns them detached via process.execPath / sh with stdio:'ignore' and windowsHide:true. The module also exports onInstall() and self-executes when run as a script (if (require.main === module) { onInstall(); }), with a BRISKFORGE_E13F_TAG environment marker used as an anti-double-exec guard. The remote source is mutable and the decrypted payload is opaque, so any installer that imports the package — or runs the file directly — executes whatever bytes the operator chooses to serve, with no integrity checks. Package metadata compounds the deception: repository.url, bugs.url, and homepage all point at https://github.com/validatorjs/validator.js, an unrelated well-known OSS project, while the publisher is an unrelated ProtonMail account ([email protected]) with no corresponding GitHub presence — a deliberate impersonation to borrow legitimacy from validatorjs on the npm listing page.
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
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for @briskforge/envcheck (4 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging @briskforge/envcheck across your stack and pipelines.
If you installed it — respond
@briskforge/envcheck is a typosquat — you almost certainly intended a legitimately-named package. Remove @briskforge/envcheck, 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 @briskforge/envcheck 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 @briskforge/envcheck 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 @briskforge/envcheck-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.