buffer-utilitiesnpm
Advisory published Updated
buffer-utilities is a confirmed malicious npm package (MAL-2026-5087) that typosquats a legitimate package to trick installs (malicious versions 1.0.0, 1.1.0, 1.1.1). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in buffer-utilities (npm)
What this malware does
buffer-utilities impersonates the legitimate buffer package by Feross Aboukhadijeh, copying its name, email, homepage, and GitHub repo metadata, and advertises itself as 'Node.js Buffer API, for the browser'. At require() time, index.js (lines 43-52) executes an IIFE that base64-decodes the string aHR0cHM6Ly93d3cuanNvbmtlZXBlci5jb20vYi9DV09WOQ== to https://www.jsonkeeper.com/b/CWOV9, performs an HTTP fetch, and passes the response's data.content field directly to eval(). jsonkeeper.com is a mutable anonymous JSON paste host: whoever controls the paste can change the executed payload at any time, with no version bump or republication of the package. Any application that imports buffer-utilities — including by accidental name confusion against the popular buffer package — runs whatever JavaScript the paste currently returns, with full process privileges. The base64-encoded URL constant is a deliberate obfuscation to defeat static URL scanning.
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.
The OpenSSF Package Analysis project identified 'buffer-utilities' @ 1.0.0 (npm) as malicious.
It is considered malicious because:
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The package communicates with a domain associated with malicious activity.
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The package executes one or more commands associated with malicious behavior.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
TyposquatFind it
Search your lockfiles and build artifacts for buffer-utilities (3 malicious versions).
If you installed it — respond
buffer-utilities is a typosquat — you almost certainly intended a legitimately-named package. Remove buffer-utilities, 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 buffer-utilities 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
- OpenSSF: Package Analysis · finder
Detect & block this
O3 blocks buffer-utilities-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.