Which versions of exnesss are malicious?

The following npm versions of exnesss are flagged malicious: 0.0.1. Treat any of these as compromised.

How do I remediate exnesss if I installed it?

exnesss 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.

I already installed exnesss — how do I know if it already compromised me?

If exnesss 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.

Is exnesss part of a known attack campaign?

Yes — exnesss is associated with the IN-MAL-2026-011245, GHSA-32p4-hf5c-v228 campaign. Packages in the same campaign often share infrastructure and payloads, so check whether any related packages are also in your dependency tree.

How do I find exnesss across my projects, lockfiles, and CI pipelines?

Search your lockfiles and build artifacts for exnesss (version 0.0.1).

Malicious package

exnesssnpm

Advisory published Aug 4, 2026Updated Nov 4, 2026

exnesss is a confirmed malicious npm package (MAL-2026-11518) that opens a backdoor for remote access (malicious version 0.0.1). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in exnesss (npm)

MAL-2026-11518

Immediate action

Remove the package, then rotate any secrets the build/runtime could reach.

npm uninstall exnesss

What this malware does

Package name 'exnesss' typosquats 'exness'. The package.json declares scripts.postinstall: 'node./postinstall.js', and postinstall.js issues an HTTPS GET to a hardcoded Burp Collaborator subdomain (hteimcuxkeb6pacscuexz4d9y04rshg6.oastify.com) on every install. This fires automatically on npm install, contacting an out-of-band interaction host that reveals the installer's network/DNS metadata to the operator of that Collaborator instance. The package provides no advertised functionality to the installer beyond the beacon.

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 'exnesss' @ 0.0.1 (npm) as malicious.

It is considered malicious because:

The package communicates with a domain associated with malicious activity.

Malicious versions

1 flagged

0.0.1

Indicators of compromise (SHA-256)

9547bba265ba397413387555d1bf269b1072ec4aba26409f22c72654c110cbf1

184796b4aafee8400786643e9f43338886de2166171c62879cfd4c023655b487

ad099cf1562a64265f95bdeb06afd1aa99185aa58559cb04e7b94efbf6ac6cc6

Detection & response playbook

Backdoor / remote access

Find it
Search your lockfiles and build artifacts for exnesss (version 0.0.1).
If you installed it — respond
exnesss 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 exnesss 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

No. exnesss on npm has been identified as a malicious package (version 0.0.1 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-011245GHSA-32p4-hf5c-v228

References

Credits

Amazon Inspector · finder
OpenSSF: Package Analysis · finder

Detect & block this

O3 blocks exnesss-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the C2 callback and severs the channel.

Malware detection Runtime egress monitoring

Explore

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