Which versions of jwtmode are malicious?

The following npm versions of jwtmode are flagged malicious: 1.0.4. Treat any of these as compromised.

How do I remediate jwtmode if I installed it?

jwtmode is a typosquat — you almost certainly intended a legitimately-named package. Remove jwtmode, install the correct package, and rotate any secrets exposed during the install since post-install scripts may have already run.

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

If jwtmode 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 jwtmode part of a known attack campaign?

Yes — jwtmode is associated with the IN-MAL-2026-006975 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 jwtmode across my projects, lockfiles, and CI pipelines?

Search your lockfiles and build artifacts for jwtmode (version 1.0.4).

Malicious package

jwtmodenpm

Advisory published Jun 18, 2026Updated Jun 18, 2026

jwtmode is a confirmed malicious npm package (MAL-2026-6093) that typosquats a legitimate package to trick installs (malicious version 1.0.4). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in jwtmode (npm)

MAL-2026-6093

Immediate action

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

npm uninstall jwtmode

What this malware does

On require('jwtmode'), decode.js immediately invokes getThirdCookie(), which performs an HTTP GET to https://jsonkeeper.com/b/AZ9ZF, takes the response field response.data.errCode, passes it to new Function.constructor('require', errCode), and invokes the resulting function with the real Node require. This is unconditional remote code execution at import time from a mutable, attacker-controlled paste host, with full Node capability (filesystem, network, child_process) via require. The package additionally impersonates auth0's jsonwebtoken: it is named jwtmode, declares author: auth0, points its repository field at a non-existent github.com/auth0/node-jwtmode, and re-exports jsonwebtoken's public API surface (decode, JsonWebTokenError, NotBeforeError, TokenExpiredError) — a brand-impersonation lure to trick developers into installing it instead of jsonwebtoken. Any project that requires jwtmode will execute whatever JavaScript the operator of jsonkeeper.com/b/AZ9ZF chooses to serve at that moment.

Malicious versions

1 flagged

1.0.4

Indicators of compromise (SHA-256)

b59454613cc025e514269f55b41a9da6a5da1db70e73e583bc79d97727e9528a

Detection & response playbook

Typosquat

Find it
Search your lockfiles and build artifacts for jwtmode (version 1.0.4).
If you installed it — respond
jwtmode is a typosquat — you almost certainly intended a legitimately-named package. Remove jwtmode, 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 jwtmode 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. jwtmode on npm has been identified as a malicious package (version 1.0.4 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-006975

References

npmjs.com

Credits

Amazon Inspector · finder

Detect & block this

O3 blocks jwtmode-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

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