Which versions of assert-json-not are malicious?

The following npm versions of assert-json-not are flagged malicious: 2.3.5. Treat any of these as compromised.

How do I remediate assert-json-not if I installed it?

Remove assert-json-not from your project and lockfile, then assume any secrets accessible to the build or runtime were exposed: rotate API keys, tokens, and credentials, and audit for unexpected outbound activity or persistence.

I already installed assert-json-not — how do I know if it already compromised me?

If assert-json-not 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 assert-json-not part of a known attack campaign?

Yes — assert-json-not is associated with the RLMA-2025-06062, RLUA-2026-01109 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 assert-json-not across my projects, lockfiles, and CI pipelines?

Search your lockfiles and build artifacts for assert-json-not (version 2.3.5).

Malicious package

assert-json-notnpm

Advisory published Dec 23, 2025Updated Mar 19, 2026

assert-json-not is a confirmed malicious npm package (MAL-2025-192711) that executes malicious code on install (malicious version 2.3.5). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in assert-json-not (npm)

MAL-2025-192711

Immediate action

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

npm uninstall assert-json-not

What this malware does

The package assert-json-not was found to contain malicious code.

Malicious versions

1 flagged

2.3.5

Indicators of compromise (SHA-256)

768ffcde67b2cb12b17ba3dc12f0f3da9551d008390ec112ea88a2b357f748f4

ad56c36eacf8881039723de4379e14983280b611dba15585274909b1a3c1b326

13fc7a73d966bbda79b81f0b859d03c20e19f392d7aba6c4b38a3008db56e9bc

Detection & response playbook

Malicious package

Find it
Search your lockfiles and build artifacts for assert-json-not (version 2.3.5).
If you installed it — respond
Remove assert-json-not from your project and lockfile, then assume any secrets accessible to the build or runtime were exposed: rotate API keys, tokens, and credentials, and audit for unexpected outbound activity or persistence.
Did it already run?
If assert-json-not 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. assert-json-not on npm has been identified as a malicious package (version 2.3.5 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

RLMA-2025-06062RLUA-2026-01109

References

Credits

Amazon Inspector · finder
ReversingLabs · finder

Detect & block this

O3 blocks assert-json-not-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.

Malware detection Runtime egress monitoring

Explore

All malware advisories How O3 detects malware Vulnerability database