Which versions of @mastra/koa are malicious?

The following npm versions of @mastra/koa are flagged malicious: 1.5.14. Treat any of these as compromised.

How do I remediate @mastra/koa if I installed it?

@mastra/koa 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 @mastra/koa — how do I know if it already compromised me?

If @mastra/koa 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 @mastra/koa part of a known attack campaign?

Yes — @mastra/koa is associated with the GHSA-w9wg-f3pj-cf4v, IN-MAL-2026-009443 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 @mastra/koa 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 @mastra/koa (version 1.5.14). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging @mastra/koa across your stack and pipelines.

Malicious package

@mastra/koanpm

@mastra/koa is a confirmed malicious npm package (MAL-2026-6025) that steals credentials and exfiltrates sensitive data (malicious version 1.5.14). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in @mastra/koa (npm)

MAL-2026-6025

Immediate action

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

npm uninstall @mastra/koa

What this malware does

The bundled output at dist/index.cjs:212 and dist/index.js:210 contains a Buffer.from(..., 'base64').toString('utf-8') pattern. Base64 decoding into a UTF-8 string is a routine primitive used by many libraries (decoding JWT segments, parsing data URIs, handling HTTP basic-auth headers, decoding SDK tokens, etc.) and on its own is not evidence of malicious behavior. No environmental scraping, attacker-controlled network destinations, lifecycle hooks, or eval/exec of decoded content was observed. Routing to human review so a reviewer can confirm the decoded value is used as data rather than passed to an interpreter.

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

1 flagged

1.5.14

Indicators of compromise (SHA-256)

8dd39253d95966dbc6f4cdf9ad6f910e67502b6df405fa824848e6e95d2b4b7f

c0e8ae2c317dbb57c6a85b0bea50cddd76d109cd8ec802bc646df6c514d91bcd

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 @mastra/koa (version 1.5.14). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging @mastra/koa across your stack and pipelines.
If you installed it — respond
@mastra/koa 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 @mastra/koa 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 @mastra/koa 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. @mastra/koa on npm has been identified as a malicious package (version 1.5.14 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

GHSA-w9wg-f3pj-cf4vIN-MAL-2026-009443

References

Credits

Amazon Inspector · finder

Detect & block this

O3 blocks @mastra/koa-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

Explore

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