Which versions of flat-cache are malicious?

The following npm versions of flat-cache are flagged malicious: 6.1.24. Treat any of these as compromised.

How do I remediate flat-cache if I installed it?

flat-cache 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 flat-cache — how do I know if it already compromised me?

If flat-cache 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 flat-cache part of a known attack campaign?

Yes — flat-cache is associated with the GHSA-8jxr-wprf-45g8 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 flat-cache 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 flat-cache (version 6.1.24). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging flat-cache across your stack and pipelines.

Malicious package

flat-cachenpm

flat-cache is a confirmed malicious npm package (MAL-2026-11971) that steals credentials and exfiltrates sensitive data (malicious version 6.1.24). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in flat-cache (npm)

MAL-2026-11971

Immediate action

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

npm uninstall flat-cache

What this malware does

npm/flat-cache version 6.1.24 is a trojanized release published on 2026-08-04 during the compromise of the npm/GitHub maintainer account behind the keyv and cacheable package families (user "Jaredwray"). Attackers pushed the malicious payload to the source repository and cut releases through GitHub Actions, so the poisoned versions reached npm with a valid, signed provenance attestation (provenance attests build integrity, not source integrity). Delivery is through the npm install lifecycle: the trojanized package.json adds a preinstall hook ("preinstall": "node setup.mjs") that runs before any project code on a bare npm install, while the normal compiled output is left intact so the package still works after install. setup.mjs downloads a standalone Bun runtime and uses it to run a second stage (shipped as Math_Symbol.js, a heavily obfuscated ~728 KB Bun bundle, referenced at runtime as math_init.js). The stealer harvests credentials from cloud instance metadata (AWS IMDS at 169.254.169.254, ECS at 169.254.170.2, GCP, Azure), AWS/GCP/Azure keys, HashiCorp Vault tokens, Kubernetes service-account tokens, GitHub Actions OIDC and org/repo secrets, and npm tokens, with a TruffleHog-style regex sweep for further secrets and private keys. Using the stolen npm identity (including npm OIDC trusted publishing) it enumerates and republishes further packages the token can reach — which, for a maintainer controlling both keyv and cacheable, gave the worm a large blast radius. Stolen findings are exfiltrated to attacker-created GitHub repositories (descriptions reading "Shai-Hulud: Here We Go Again") and to destinations resolved over DNS, and autostart hooks are planted in the repository's .claude/ and .vscode/ configuration to run the loader when a developer or AI coding agent opens a clone. Treat any environment that installed this version (with install scripts enabled) as fully compromised and rotate every reachable credential. Part of the August 2026 npm worm that poisoned 400+ packages across many organizations.

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

6.1.24

Indicators of compromise (SHA-256)

437a2cf9e9142608f18fc633cd57ba2321c530a9020c6bc988748612a9ebdaec

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 flat-cache (version 6.1.24). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging flat-cache across your stack and pipelines.
If you installed it — respond
flat-cache 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 flat-cache 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 flat-cache 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. flat-cache on npm has been identified as a malicious package (version 6.1.24 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

GHSA-8jxr-wprf-45g8

References

Credits

Aikido Security · finder
SafeDep · finder
Socket Threat Research Team · finder

Detect & block this

O3 blocks flat-cache-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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