Which versions of jwt-logger are malicious?

The following npm versions of jwt-logger are flagged malicious: 2.1.9, 2.4.9, 2.5.0. Treat any of these as compromised.

How do I remediate jwt-logger if I installed it?

jwt-logger 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 jwt-logger — how do I know if it already compromised me?

If jwt-logger 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 jwt-logger part of a known attack campaign?

Yes — jwt-logger is associated with the GHSA-rpqx-cp2g-55w5, IN-MAL-2026-019687, IN-MAL-2026-019686, IN-MAL-2026-019688 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 jwt-logger across my projects, lockfiles, and CI pipelines?

Search your lockfiles and build artifacts for jwt-logger (3 malicious versions).

Malicious package

jwt-loggernpm

Advisory published Sep 5, 2026Updated Sep 8, 2026

jwt-logger is a confirmed malicious npm package (MAL-2026-15991) that opens a backdoor for remote access (malicious versions 2.1.9, 2.4.9, 2.5.0). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in jwt-logger (npm)

MAL-2026-15991

Immediate action

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

npm uninstall jwt-logger

What this malware does

The package is published as a trivial JWT logging helper but its main module (jwt-logger.js) is a heavily obfuscated string-array dropper. On require(), it creates a hidden directory under os.homedir()+'/.cache', writes an obfuscated second-stage JavaScript payload plus a synthetic package.json declaring runtime dependencies (axios, better-sqlite3, node-machine-id, socket.io-client, with ffi-napi/koffi on Windows), and spawns node (process.execPath) on that payload with {detached:true, stdio:'ignore'} and unref(), so the second stage keeps running after the parent exits. On Windows it resolves %WINDIR%\System32\wscript.exe to launch a.vbs form of the payload, or falls back to cmd.exe /d /s /c with windowsVerbatimArguments to run without a visible console. All runtime strings are hidden behind an obfuscator.io-style rotated string array with a base64/URL decoder. package.json attributes authorship to 'Blake Embrey' [email protected] and the README carries blakeembrey.com/travis/coveralls badges, none of which corresponds to the shipped code. package.json additionally lists 'jwt-logger':'^2.3.7' as a dependency of itself (this artifact is 2.1.9), pulling an unpinned newer publisher-controlled version into every installer at install time. The socket.io-client dependency and detached background node process are consistent with a C2-controlled second stage.

Any computer that has this package installed or running should be considered fully compromised. All secrets and keys stored on that computer should be rotated immediately from a different computer. The package should be removed, but as full control of the computer may have been given to an outside entity, there is no guarantee that removing the package will remove all malicious software resulting from installing it.

Malicious versions

3 flagged

2.1.92.4.92.5.0

Indicators of compromise (SHA-256)

65564206b619c42f36cffb6489b5558060cbb7eb61be4827b71c7b299f84fb65

61326f7099e9170425d9321289db212c9c8ec51d32ce5ce02c8d234f08fc0995

b56e3f2d5fab071637ba7688de6c2a9c3d1c1846b6ec939b82eb2c8e9ff03956

c6cdf9df6d9ecec6fe2a96487430c6ca18a00d31eb95981fa166a0f30caa578b

Detection & response playbook

Backdoor / remote access

Find it
Search your lockfiles and build artifacts for jwt-logger (3 malicious versions).
If you installed it — respond
jwt-logger 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 jwt-logger 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. jwt-logger on npm has been identified as a malicious package (versions 2.1.9, 2.4.9, 2.5.0 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

GHSA-rpqx-cp2g-55w5IN-MAL-2026-019687IN-MAL-2026-019686IN-MAL-2026-019688

References

Credits

Amazon Inspector · finder

Detect & block this

O3 blocks jwt-logger-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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