Which versions of unico-check are malicious?

The following npm versions of unico-check are flagged malicious: 9.9.9. Treat any of these as compromised.

How do I remediate unico-check if I installed it?

unico-check 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 unico-check — how do I know if it already compromised me?

If unico-check 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 unico-check part of a known attack campaign?

Yes — unico-check is associated with the IN-MAL-2026-006698 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 unico-check across my projects, lockfiles, and CI pipelines?

Search your lockfiles and build artifacts for unico-check (version 9.9.9).

Malicious package

unico-checknpm

Advisory published Jun 15, 2026Updated Jun 16, 2026

unico-check is a confirmed malicious npm package (MAL-2026-5830) that opens a backdoor for remote access (malicious version 9.9.9). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in unico-check (npm)

MAL-2026-5830

Immediate action

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

npm uninstall unico-check

What this malware does

package.json declares a preinstall lifecycle hook that runs curl against https://webhook.site/fe1246c2-ac04-4493-b223-fe34ba26b79f, passing the installer's hostname, current user, working directory, full uname -a output, and $HOME as query parameters. The beacon fires automatically on npm install with no user interaction. The package ships no source files, declares no main entry, and uses the implausible version 9.9.9 — the canonical shape of a dependency-confusion / typosquat reconnaissance package targeting builds that may resolve a private unico-check from the public registry. The package's only effect on installation is to leak host identifiers to an anonymous, attacker-controlled webhook.site bin, staging follow-on compromise.

The OpenSSF Package Analysis project identified 'unico-check' @ 9.9.9 (npm) as malicious.

It is considered malicious because:

The package executes one or more commands associated with malicious behavior.

Malicious versions

1 flagged

9.9.9

Indicators of compromise (SHA-256)

1945d7aee54e60800e30f150e6db8042fa3aee9ea99f6b5a4ab14e2a1c26571d

61af12e58a8af18142c41410d07328ba0dbfb7e79b145d84b2389444c27b2abc

Detection & response playbook

Backdoor / remote access

Find it
Search your lockfiles and build artifacts for unico-check (version 9.9.9).
If you installed it — respond
unico-check 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 unico-check 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. unico-check on npm has been identified as a malicious package (version 9.9.9 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-006698

References

npmjs.com

Credits

Amazon Inspector · finder
OpenSSF: Package Analysis · finder

Detect & block this

O3 blocks unico-check-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

All malware advisories How O3 detects malware Vulnerability database