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 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.

Is exnesss part of a known attack campaign?

Yes — exnesss is associated with the IN-MAL-2026-011245 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?

Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for exnesss (version 0.0.1). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging exnesss across your stack and pipelines.

Malicious package

exnesssnpm

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.

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

Detection & response playbook

Backdoor / remote access

Find it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for exnesss (version 0.0.1). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging exnesss across your stack and pipelines.
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 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 exnesss 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

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-2026-011245

References

npmjs.com

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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