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 built to steal secrets, so assume every credential the build or runtime could read is compromised. Remove it from your project and lockfile, then rotate ALL exposed secrets — npm/registry tokens, cloud keys, CI/CD secrets, SSH keys, and any .env values — from a known-clean machine. Audit logs for unauthorized use of those credentials.

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

If jwtmode 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 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?

Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for jwtmode (version 1.0.4). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging jwtmode across your stack and pipelines.

Malicious package

jwtmodenpm

jwtmode is a confirmed malicious npm package (MAL-2026-6093) that steals credentials and exfiltrates sensitive data (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

Credential / info stealer

Find it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for jwtmode (version 1.0.4). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging jwtmode across your stack and pipelines.
If you installed it — respond
jwtmode is built to steal secrets, so assume every credential the build or runtime could read is compromised. Remove it from your project and lockfile, then rotate ALL exposed secrets — npm/registry tokens, cloud keys, CI/CD secrets, SSH keys, and any .env values — from a known-clean machine. Audit logs for unauthorized use of those credentials.
Did it already run?
If jwtmode 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 jwtmode 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. 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 credential exfiltration and severs the channel.

Malware detection Runtime egress monitoring

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